Nokini Atoll Pt. 01

Claire found herself walking a cold city block, just to get some relief from her claustrophobic apartment, and Greg. The startup they worked at was pretty small, with everyone fresh out of college and seeing a lot of each other in the long hours. So it hadn't raised any red flags when she started dating Greg. Yes, he was higher in the org chart, but it was a small chart, and the job titles were very much in flux. He said if she stuck around five years, she'd be at the director level too. In those five years, she imagined them getting married too, and starting a family.

That was all before she found Greg's phone unlocked for once, mistook it for her own at first, and came across a series of texts with another woman. They weren't even sexts, they weren't romantic, they were just logistics. Always sorting out the time and place, over and over again.

Things had spiraled quickly after that. It wasn't like she could work with him and be civil about it. Not when she saw his attention already starting to turn towards another woman in the office. And thus she found herself out of a job. She couldn't go on living with him, but she also couldn't afford to move out. About all she could afford was a complete stranger's spare bedroom, with a side of bedbugs and stalking. No thanks! But she didn't know what else to do.

She wasn't sure who to even talk to about this. She just felt so stupid about it all. About hitching her career to her relationship and vice versa. So many eggs in one flimsy basket, and the whole time, she'd felt smug about not being broke all the time like her old college friends. She could already imagine how her brother Kyle would make fun of her. And at age 18, it wasn't like he was in a position to do much to help. Nor would Uncle Theo, who basically only gave Kyle a place to crash long enough to finish high school. He wouldn't have even offered that, if mom hadn't written it into her will.

Claire noticed a flier taped to a light pole. "Research participants needed. One year commitment." It showed a sandy beach with turquoise water. A web address and QR code to find out more.

This kind of flier was such an old-fashioned thing. Anyone could easily get more eyes by posting online. But it also carried a little impression of legitimacy because it was local, and wasn't free. Someone paid for the photocopies, and the tape. Someone walked around and put the fliers up. If this were something truly nefarious, they wouldn't be drawing attention to it in broad daylight like this.

She scanned the QR code and skimmed the site. The info there was sparse too. A sociological study that would require relocation, and would last up to one year. Selected participants would be compensated.

Some parts of the website said $1 million, other parts said half that, which was a little confusing. Either way, that number made Claire's imagination run wild. Yes, she might spend a year of her life doing something--probably not manual labor, or they would've specified that--but it might not be anything all that bad, and at the end she'd have enough to live on for quite a while. It was a large sum, but not large enough to sound like a scam for sure.

She googled the research institute's name, and found a basic page, with faculty portraits. The kind of boring, uninformative page so many academic institutions seemed to have.

Claire didn't know enough about this to jump at the opportunity, but she also didn't know enough about it not to. Seeing that thinking it over wasn't going to lead anywhere, she paused on the sidewalk long enough to fill out the short sign-up form.

Afterwards, she felt right about doing it, even if it wasn't a sure thing. They did say "selected" participants, after all. But at least it was something. An alternative to letting this thing with Greg ruin the whole year. Even if this research study didn't come through, maybe she could find some other way to go somewhere far away and make a clean break.

***

Kyle knew he was behind on finding a summer job, but it felt like he was always behind on everything. Behind on studying for final exams. Behind on applying to college. Every time he sat down at the computer, he knew he needed to find a job, or he'd have to face another "tough love" lecture from Uncle Theo about personal responsibility, and boots with straps. Kyle had never seen boots with straps.

Maybe Uncle Theo would let him stay over the summer until he had a dorm room to move into, but his uncle would clearly rather not. It was especially doubtful if Kyle didn't line up a job, and couldn't contribute to household expenses like Theo expected him to. The stipulations in Mom's were running out, as of Kyle's high school graduation day.

"Can't you spend a summer with the forest service?" he'd suggest. Somewhere far from here, was always the subtext. And it wasn't as though Kyle wanted to stay somewhere he wasn't welcome.

On a jobs site, Kyle came across a listing that said, "Research participants needed. One year commitment."

In the salary field underneath, it said $500k. That had to be a typo, but Kyle clicked through, curious. It wasn't exactly what he was looking for, but for that kind of money, he could consider a change of plans.

There weren't many details to be found, but the $500k number was repeated elsewhere. And there weren't any requirements or qualifications listed either.

He filled out the form without a doubt. Maybe it'd go nowhere, but Kyle was taking a "spray and pray" approach to this job search. Why self-reject, when you can make other people do it for you?

The form was just about who he was, and how to contact him. It wasn't even harvesting any sensitive data. At worst, they could sell his data to telemarketers or something.

Kyle didn't even count this as one of his job applications for the day--it was such a vague and uncertain prospect--but it got his momentum rolling, and he ended up applying to a dozen other jobs that day, and feeling pretty good about his progress. At least until Uncle Theo came home and belittled it.

The next morning, his cellphone buzzed. Uncle Theo, on his way out the door, gave him an annoyed look. Kyle couldn't believe that. How could he be annoyed, when this might be any of those dozen companies calling him back?

"Kyle Schaumburg, I'm with the Nokini Institute. We have some screening questions to go through, if you don't mind?"

"Sure," Kyle said, wiping the sleep from his eyes.

"If selected, would you be able to relocate to the institute for the duration of your participation in the study?"

"Yeah," he said at first. "Sorry, I guess I forgot. Where?"

The voice on the other end waited a moment, and added, "Is that a yes or a no, Mr. Schaumburg?"

How bad could it be, he wondered? He hadn't gotten to travel much, but he'd always enjoyed it when he had.

"Yeah, it's cool," he said. "Yes."

"And would you be able to spend up to one full year participating in the study?"

"Look, I'll have to defer my college admission, but I'm pretty sure I'd be able to do that," Kyle said, and the half million dollar figure loomed in his mind again. He might go for it whether or not the college would let him defer. "You can put me down as a Yes."

"Can you list your family members for me, Mr. Schaumburg?" the voice said. "Briefly please, we've got lots of calls to make today."

"Okay, there's mom and dad. Shit. No. They're... passed. There's my sister Claire, and Uncle Theo, and... I dunno, second cousins or some--"

"Thank you. We'll be in touch soon."

***

Claire packed her bag. A duffel's worth of clothes was all she had left; the rest was already packed away in a self-storage cubby.

"Hey," Greg said from the doorway. "I said 'hey'. What's th--where are you going?"

"You know I can't just keep staying here," she said, not bothering to turn towards him. Not when tears threatened to fall. "I can't keep paying half the rent, I can't keep getting in the way of you and Theresa--don't deny it--and I can't keep sleeping in a bed that you might slip into if you get drunk and nostalgic."

"But where--"

"I don't even know," she said, zipping up the duffel. "Some scientific study. But they're picking me up shortly, and it's none of your business anyway."

She hated that, even now, he was the one she was tempted to lean on with her tears and uncertainty. She'd done it before, many times, when they were together, and she knew exactly how comforting his embrace could be. How easy it was to entrust herself to someone a bit older and more experienced with the world. At least that temptation wouldn't last.

"Can I at least--" he began.

"No," she said, not even knowing what he was about to ask, or offer. Whatever it was, she couldn't let herself accept. Couldn't even risk letting him say it. There was no redeeming this, no putting them back together. "Sorry, but... no."

A gray rental SUV picked her up out front of the building. The driver didn't know anything more than she did. She was brought to the kind of airport she'd never been to before. There were no lines, no gates. Private planes only.

Her driver took her right to the jet, and she climbed the steps up to the cabin, feeling like Taylor Swift or something. The inside was smaller than any of the consumer-grade planes she'd been on, but there were still rows of seats, and one in particular for her.

The seat next to hers was occupied. "Kyle?"

He turned to her. It really as him, and his face went through a number of expressions.

"Claire, what are you doing here?" he asked.

"I signed up for this year-long research--" she began, eager to skip over the part where she broke up with her boyfriend and lost her job in a most spectacular train-wreck fashion.

"Me too," he said.

"This is me," she said, eager to get seated. The plane's crew weren't hurrying them yet, but they were shutting the overhead bins, and the engines were coming to life.

It felt stupidly cramped, to squeeze in next to her brother on a long-haul private jet, but it was also unexpectedly comforting. She'd spent so much time trapped with Greg lately that she'd been touch-deprived. Not that she could ever bring a guy home.

The two of them quickly exchanged notes, about what little they knew.

"Was the question about family weird?" Kyle asked.

"I don't know," Claire said. "Maybe they were after an emergency contact. Or--"

"With both of us on this plane together? Either they picked us because we're related, or it's the biggest coincidence ever."

"We could ask the other passengers, but I get the sense they can't or won't tell us much," Claire said.

She'd noticed that the others on the plane looked like they belonged to a particular ethnic group--based on their skin tone, their clothes, and what little they said to each other, in a language she didn't recognize. She wished she knew enough that these could be clues about their destination.

It was an extremely long flight. The crew periodically came around with meals, and eventually Kyle slumped over against her shoulder, unable to keep his head up. Claire envied his ability to sleep wherever, and resigned herself to resting her eyes until they landed. But the feeling of her brother against her, it reminded her how nice it could be to just sleep with someone. Not in a sexual way, just catching z's together. Without even deciding to, she drifted off as well.

***

Kyle's excitement about this adventure had somehow turned to trepidation when he boarded the plane. It was only then that he started running through worst-case scenarios. Maybe he was flying his organs overseas to be harvested, he had no idea.

When Claire showed up, it cast everything in a new light. On one hand, it took some excitement out of the adventure if he wasn't leaving behind everyone he knew. So whatever he was in for, it wasn't what he had initially imagined, and somehow that made it an even bigger unknown. On the other hand, they would be safer together.

After the flight came a drive to a dock, and then a boat ride, blindfolded. This was even more mysterious, and he wondered again if they were going to just be taken somewhere and killed. But where or not the half-million payout was real, the Nokini Institute had clearly invested a lot in them already, just in travel expenses alone. And it helped that even blindfolded, he could feel Claire's warmth next to him.

The boat's engine quieted down, and the pilot removed their blindfolds as the boat idled into another dock.

On the dock stood a man in a lab coat. "Sorry about that, Mr. and Miss Schaumburg. It's just a precaution so that no one unauthorized can interrupt our work here."

Kyle climbed up on the dock first, but lost his footing and stumbled. When he was stable on his sea-legs, he reached down and helped Claire haul herself up. That was when he recognized her duffel bag from her time on the swim team years ago.

"I'm Dr. Harald Flavius," the man in the lab coat said. "Or perhaps not? Who knows. Follow me this way, please."

Kyle exchanged a look with Claire, about how strange this all was. She reacted the same way back at him.

They followed the doctor to a building away from the shore. Dr. Flavius said, "We must perform separate orientation interviews. I hope you lovebirds don't mind being apart for a few minutes."

It almost didn't register with Kyle at first, as he followed Dr. Flavius into one room, and a female doctor directed Claire into another. The room was completely silent when the door shut.

Kyle took a seat across the desk from Dr. Flavius. The latter began, "Firstly and most importantly, I need you to sign this NDA. I'm sorry, non-disclosure agreement. It is internationally binding."

"Why?" Kyle asked.

"It's a standard thing, Mr. Schaumburg," the doctor said reassuringly. "If study participants were to go public about what this study is about, it would have a tainting effect. Future participants would know more than they should when they arrive. Future participants might choose to participate or not, based on that additional information. It would very much compromise the scientific method, I'm afraid."

Kyle wasn't entirely sure about that, but he got the point, and signed.

"Good. Now, I have a series of questions I have to ask you. Every question I'm about to ask you is the same set of questions we ask all participants. Please answer honestly. First, are you sexually active?"

"Um, can you be more specific?" Kyle asked, sweating already.

"Let me see. Have you had sex?"

Kyle was half-tempted to ask for further clarification, but then he decided that whatever the doctor's idea of sex was, Kyle had done something that ought to fall into that category. "Yes."

"How many sexual partners have you had?" the doctor quickly moved on.

"Three. No wait, four."

"How often do you masturbate?"

Kyle felt like a frog in a boiling pot, wondering how it'd gotten to this point. Whatever, he thought. This could be a medical baseline question.

"I'd say once every two or three days," he said, and that was only because he'd been living with Uncle Theo, and opportunities had been few.

"Would you say your sister... Claire is attractive?" the doctor asked, consulting his notes to fill in the name.

"I guess so. Sure," Kyle said. Claire was a little much for guys to handle sometimes, but Kyle recognized that she was curvy and had a contagious smile. He wasn't too prudish to acknowledge that his sister was the kind of woman who could get male attention, and deserved it.

"Have you ever been attracted to her?"

Kyle's throat was getting dry now. His mind flashed back to a time he'd seen her doing laps in the pool, her head down, and he hadn't recognized her at first. Almost mistook her for a girl his age, not someone five years his elder. The way her hips glided through the water, the way her buttocks flexed when she kicked.

"No," he said.

"Have you ever had any sexual contact with your sister?" Dr. Flavius asked, as if this were part of his medical history.

"I just said..." Kyle began. Although you could have sexual contact with someone you weren't attracted to. Like that girl Lisa at that party. His number four. The night of the car crash. "No. Never."

The doctor set down his pen with an audible thud. "We're willing to accept you into the study, Kyle. The two of you. Which means I can now share with you what this study is about..."

Kyle had lost the thread a bit, but he tried to focus on what was coming next.

"Genetic studies have determined that incest has occurred amongst our ancestors at a rate higher than was previously identified via other methods of research, and here at the Nokini Institute, we are conducting a study to better understand this phenomenon," Dr. Flavius went on. "We've brought you here to this remote location to study and observe the behavior of sibling pairs. Upon completion of the study, you'll be well compensated, because of the considerable challenge we've had in finding qualified participants like you: a brother and sister who can put their normal lives aside for up to an entire year."

"Doctor, what exactly are you asking us to do?" Kyle asked, worriedly.

"Nothing," Dr. Flavius replied with good humor. "As much 'nothing' as you like! You and your sister will simply be living alone for one year, under experimental conditions. We'll observe and periodically gather data."

"You're saying, we can just chill for a year, and collect a quarter million each?" Kyle asked. This wasn't sounding like a challenge at all. Kind of a weird way to spend a year, maybe not something he'd ever want to tell anyone about, but it'd more than pay for itself. This was a free ride to college, and then some. "What's the catch?"

"Half a million each," the doctor corrected. "No catch. You must abide by the NDA, which you already signed. You can choose to leave at any time and end your participation in the study, but if you leave early, your stipend would be forfeit."

"But you said 'up to a year', right?" Kyle said. "Does it always take a year, or no?"

"There are certain circumstances under which we might agree to release you early," the doctor said. "Sorry, let me use consistent terminology. We might agree to release you from your participation early. Mainly that might occur if one of you needs medical care, such as a cancer or pregnancy..."

Given the purpose of the study, it grossed Kyle out to think about the possibility of pregnancy. It must happen, for the doctor to mention it. But that wouldn't happen to them, Kyle thought. As long as Claire wasn't pregnant already.

"Any other questions?" the doctor said, getting up. "If not, you may wait for Claire outside. In order to participate, you must both agree."

Kyle sat on the edge of the concrete building foundation. It was warm, even under an overcast sky. Small lizards crawled around quickly. Over the sound of the ocean surf, he didn't hear Claire approach. She sat down next to him, a nearness that he found himself second-guessing now.

"I had no idea it was going to be something like this," she said.

"You couldn't have known," Kyle said.

She took out her cellphone. It had no signal. "Want to waste a year here?"

"It's an easy half mil each," he said, for the sake of argument, not fully convinced. "I don't see what the challenge is."

She looked at him inquisitively. "Me neither, I guess. But we can never, ever talk about it. And I'm not just talking about the NDA."

"Are you pregnant, by any chance?" he asked.

"What??"

Kyle immediately regretted asking. "Just... something they said. Could've gotten the money quicker if you were."

"Well, no. I am definitely NOT pregnant right now. And glad of it," she said. "Not that it's any of your business."

"Hang on," Kyle said. "You're saying when I become an uncle, it won't be any of my business? Fuck that. If you ever have kids, I'm gonna be there for them no matter what." Not like Uncle Theo, he thought.

"Okay, fine," Claire said. "Kyle, we shouldn't have even come here. This is all so messed up. If you'd called me and told me about this, I would've talked you out of it."

"You would've tried," he said. "But I didn't call, did I. If you don't want to sign up, that's totally fine, but... it's easy money, and I am kinda liking the view here."

He took in the beach that curved away from them. Even if Claire backed out now, this had been some kind of adventure. This was still somewhere new and beautiful.

Claire sighed. "Alright. I was this close to saying no, but... we have to remember, anytime it gets weird or unpleasant or anything, we can decide to leave. Either of us can. Right?"

"Yeah, of course," Kyle said.

He was actually kind of excited. Not so much about the creepy incest research. Not even about spending a year with his sister. But just spending a year free of the constant real-world grind. But he tamped down that excitement somewhat. He worried Claire would take it the wrong way.

There were footsteps behind them. Dr. Flavius handed them each a clipboard with a consent form. The two siblings filled them out quickly, as if their consensus could break at any moment.

MONTH 1

A member of the staff--a guy built more like a lifeguard, with thick arms, short shorts, and a deep tan--let them down the beach, to where Kyle noticed a cottage, built up on stilts. It was a long walk, and extra tiring on the sand, which was damp and spongy.

"This is about as dry as it gets," their guide said. "Don't try to get to the office at high tide. We've got your place all wired up to page us if you need something, and then we'll come to you."

They climbed the stairs to the cottage, and Kyle noticed it was a lot more tidy and modern than he thought from afar. There was a big sliding glass door on the side leading out to the deck. Running water, at least in limited supply. Solar panels on the roof. A bed for each of them. Other than a bathroom, it was an open floor plan. There was an air conditioner and everything inside, but it was set a little warmer than he expected.

"Is there a way to turn down the temperature?" Kyle asked.

"No, certain things are only controlled from the office," their guide said. "For consistent experimental conditions."

Kyle gave Claire an incredulous look. What the heck.

"There's a week's worth of meals here, in the fridge and the freezer and the cupboards, things you can just heat up and eat. There'll be more delivered on a weekly basis. We'll also process your laundry for you," the guide said. "Once a month, we'll also be conducting psychological surveys of each of you independently. The digital calendar on the wall here will remind you when that's coming up."

'Where else would we be?" Claire asked, not just rhetorically.

"I mean, the beach here is great, the water is immaculate," their guide said, his voice turning reverent. "Just please exercise water safety, okay? I really don't want to have to come rescue either of you. Anything else?"

Kyle looked blankly to Claire, but she shook her head, and the man departed. The siblings made fun of him ruthlessly as soon as he was gone.

He flopped down on the bed, and let his jet lag catch up with him. The room was warm enough that he didn't even have to climb under the bedding before his eyes drooped closed.

***

Claire let Kyle sleep. She was exhausted too, but she could hold out for the night. She slipped into the bathroom to change into her bathing suit, and then step out onto the deck in her bare feet. The sunlight was warm on her skin, but she could already feel it penetrating. She had to be extra careful at this latitude.

The dry sand piled around their cottage was toasty underfoot, so it was sweet relief when she reached the water. To either side, the narrow strip of beach stretched off in either direction in either direction, eventually forming one large curve. The office was only a speck in the heat-shimmer distance now.

Stronger waves pushed against the outside of the curving beach, but the inside was an enclosed bay, and the water there wasn't too warm or too cold, but just right.

As she started to swim, Claire realized how long it had been since she had before. Had it really been since high school? The swim helped work the tension out of her muscles, her whole body finding its rhythm and working in concert.

Her mind descended into a meditative flow state, where all her fears and worries couldn't reach her. The prospect of spending a year here was daunting all on its own, but also this experiment being done on them. Surely some of the siblings they brought to this place had to be normal like them, right? She and Kyle could just be a dud for the experimenters. They could be part of the control group. But this place was beautiful, and if she got to swim every day, she could see herself getting used to this.

Claire surfaced, and glanced back towards the cottage. She'd come a long way, though it was tiring and slower than walking. Kyle was out on the deck now, with a pair of binoculars. Claire wondered if he was looking for her, maybe even worrying about her. She doubled back.

She stepped out of the water and dried herself off with a towel before climbing the steps to the deck.

"Were you watching me?" she teased, noticing a tension in Kyle's posture.

"N-no," he said. "I just noticed, there are a couple cottages like this one, around the edge of the atoll. Looks like one of them's occupied."

"And you're out here pointing binoculars at them."

"I don't think they mind," Kyle said. "The man waved in my direction. Want to see?"

Claire took the binoculars--loaners from the cottage, she guessed--and looked where Kyle was pointing. Now that he mentioned it, there was another cottage there, barely visible with the naked eye.

With the binoculars, she could see how similar it was to hers, with a big sliding door facing the bay. The lights were on inside, and she could see the two of them in silhouette. A man, tall, with broad shoulders, and a short woman with full breasts. They were naked, not that she could see their individual bits very well. As she watched, they stepped together into a kiss, one naked body pressing hungrily against the other. It reminded Claire of the moments like that she'd experienced, and how long she'd gone without, because of the stupid Greg situation.

Claire abruptly remembered where they were, and wrenched her gaze away, bringing the binoculars down. She turned to go inside.

"Can I... have those back?" Kyle asked.

"Kyle, those people are test subjects like us. They're brother and sister," she said. "I don't think we should watch them."

"For all we know, that cottage could be just a normal time-share," Kyle said. Claire rolled her eyes. "Okay. You're right."

She stepped inside, pulling the door shut behind her, well aware that it didn't really give her any privacy. Then she grabbed clothes to take into the bathroom with her.

Just a brief shower, but the warm water cascading down her body felt divine, lighting up her senses. A warmth between her legs called for her touch, and she leaned against the shower wall, hot water pouring down on her head, and tried to hold in her gasps as she quickly gave herself a much-needed climax. She might have rather spread her legs wide on the bed and taken her time, but there were a lot of things she wanted and couldn't have, under the circumstances.

Afterwards, she felt clean and cozy, even before she changed into her thin pajamas.

Sunset was striking enough that she had to go out on the deck again to take it all in, before heating up meals for the two of them in the microwave. It was some kind of simple dish, roast chicken and vegetables over rice. Tasty and healthy at the same time.

Then exhaustion was really piling up. She and Kyle went to sleep in their beds. Before she turned out the light, she said, "This isn't how I would've wanted it, but it's good to be traveling with you again."

"You too," he replied sleepily.

***

Kyle awoke first, but stayed in bed. For modesty he wore shorts and a t-shirt to bed, and that plus the bedding, plus the warmth in the cottage, meant he slept a bit feverishly. He was plagued with dreams of sweaty bodies against his, and he awoke with a firm erection. He'd have to get up eventually, but he did not want Claire to see him with that.

He wasn't even entirely sure why. Surely she had to know this was a common phenomenon, even if she'd never seen the physical evidence of it in her brother. It shouldn't be a big deal, and he knew he shouldn't be making it a big deal, but knowing the kind of experiment they were taking part in, he didn't want her to think this erection was about that somehow.

As he pretended to sleep, eventually Claire got up, changed into her bathing suit, and slipped outside. With half-lidded eyes, Kyle watched her backside recede. It brought him back to that day at the swimming pool again, and his erection throbbed. No, Kyle thought. Stop.

He got up and went to the bathroom. He could wait for his erection to wane on its own, however long that would take, or he could finish it off by his own hand. Kyle started stroking himself, hurrying, not savoring the sensation. He flitted through mental images, looking for something he could jack off to.

Normally there'd be the entire internet's worth of porn, and he remembered little bits of it here and there, but mostly his mind drew on his own experiences. The other women he'd been with. The man and woman across the bay. No. Claire's graceful, undulating movements in the water. No. He kept trying to focus himself back on his own past escapades, but those memories were all more distant. All drained of tactile detail. He brought himself to orgasm, but it was rushed, frustrated, almost uncomfortable.

After cleaning himself up, Kyle set their small dining table for breakfast, and made coffee successfully on his third try with the machine.

***

Claire was surprised at how quickly the first month had gone by. An entire month was longer than any vacation she'd ever taken as an adult. If this was the end of their vacation, she'd go home feeling fully decompressed.

But even after a month in this little beach cottage, she wasn't tired of it yet at all somehow, somewhat to her surprise. Maybe the slow pace of life here suited her more than she realized, or maybe she was adapting to it. Back home, she was always in the habit of bombarding her senses. Scrolling social media while watching a TV show. Here, there were just some random leftover books. Stephen King, John Grisham, Danielle Steele, and so on.

The two of them had settled into a cadence that broke up the day and made it pass easily. She remembered what it had been like growing up with Kyle, all the ways they used to get on each others' nerves--sometimes on purpose--but he was an adult now. And it had always been easier to be enemies when they had their parents around to hold them together. Without mom and dad, both of them recognized that they were pretty much all they had.

The comms and tech stuff had been sitting idle since they arrived (and determined it couldn't get them streaming movies). So it was a bit startling to hear Dr. Flavius's voice.

"Ahem. We're ready to perform your monthly evaluation. Please join the video call as soon as you're ready. Just one of you, please."

"I'll duck out," Kyle said.

Claire laughed a bit as he left. He seemed so nervous sometimes. It took her a minute, but she figured out how to wake the wall-mounted tablet, and Dr. Flavius's face appeared on it.

"Well done, Claire. I knew you'd figure it out," he said. "Are you ready to begin?"

Claire brought a chair over, to sit opposite the doctor. "Yes, I'm all situated now."

"How are you feeling today?" he asked.

"I'm feeling..." she began, but had to pause to take inventory. "Pretty good, actually. I left a bunch of stress behind at home, but here, I'm free to just be. The exercise, the fresh air, the food, it's been really good for me."

"How are you and your brother getting along?"

"It's been pretty easy, sharing the cottage with him. We used to get on each other's nerves a lot, but he's all grown up now, and he knows how to cohabitate as an equal adult, which was a pleasant surprise. Sorry if I'm rambling..."

"Not at all," Dr. Flavius said with a reassuring smile. "In this past month, have you kissed Kyle?"

Claire paused, caught off guard by the question. Was she supposed to have kissed her brother? Thinking back, she realized she hadn't kissed him at all, and couldn't remember the last time she had. But it was a normal thing for siblings to do, wasn't it? Not like making out, just... kissing.

At the same time, the question reminded her of the study they were taking part in. Talking about this stuff was the price they had to pay, to be able to stay in paradise for a whole year and walk away with a pile of cash.

"No, I have not," she replied.

"Would you like to?" the doctor asked.

"It's not that I'm against it," she said. "I guess it just didn't occur to me."

"Is Kyle attractive?" the doctor asked.

Claire had encountered this question during their initial evaluation, and she gave the same answer now. "Sure. He's physically fit, he's kind. What's not to like?"

"Are you attracted to him?"

Her first instinct was to give a simple no response. But she took a second to reflect. Over the past month, she'd never found herself admiring Kyle in that way. And while she sometimes found herself getting aroused, it wasn't prompted by him.

"No," she said.

"Have you had any sexual contact with... Kyle?" His hesitation made it clear that he was reading off a standard list of questions and filling in the names as he went.

Claire had suspected they'd ask about this, and while the question itself mildly unsettled her, she knew this was exactly what they were studying. And she felt like she had nothing to hide anyway. They'd lived so many years together, a lot of it under the same roof, without ever crossing a line, without ever even wanting to. They could easily get through another year together without their relationship turning weird.

"No," she said again.

"Have you ever wanted to?" the doctor asked.

"Not at all," she said with a soft laugh.

"Are you menstruating?"

"Yeah, that happened a couple weeks ago," Claire said. "Actually, about that: I only have a week's worth of pills left at this point," she said. "I should've stocked up, knowing I was going away for a year, but I didn't really know it'd be this... remote."

She hesitated to bring this up at all, but she talked herself into it nonetheless. There shouldn't be anything weird about asking for a medication refill, after all.

"Birth control pills," Dr. Flavius guessed. Claire nodded. "I'm sorry, but providing those would be against our experimental protocol. We should've asked you to discontinue them when you arrived. Do you anticipate needing--"

"No!" Claire blurted out. "Nothing like that. I've just been on them for so long, I figured... It's fine, really."

"Glad to hear it," Dr. Flavius said. "Do you have any other requests? Adjustments to the meals, perhaps?"

"I don't suppose we can get an internet connection out here?" Claire asked.

The doctor laughed. "I wish we could, but no."

"I could use some more books then," Claire said. "I'm going to get through all of the ones here pretty soon."

"I think we can accommodate that," Dr. Flavius said. "Anything in particular?"

Claire's reading list was an ocean away. She hadn't expected to enjoy the leftover paperbacks as much as she had. "Whatever's around."

"Of course. Please send your brother in next."

MONTH 2

Claire was out taking her morning swim, which meant Kyle had the cottage to himself for about fifty minutes. Plenty of time to get himself off, and not even have to rush it. Lord, he needed the relief, and needed more than a frantic wank once in a while.

He pulled down his shorts and sat on his bed, gently teasing his erection to full stiffness, full sensitivity. But he really needed something, anything to occupy his imagination. After all, his immediate situation wasn't giving him much to work with, and if there was one person he couldn't afford to fixate his fantasies on, it was Claire.

Kyle grabbed the binoculars. With effort, he could hold them to his eyes with one hand and stroke himself with the other. From his bed, he had a narrow view out across the bay to the cottage on the opposite beach. It wasn't like he could go stand at the sliding glass door and pull on his dick, but from his bed, with the lights out, there was no way Claire or anyone else would know what he was up to.

In the other cabin, they were just getting up. Two people in one bed. Kyle wanted to believe otherwise, but even he recognized that the man and woman were the same race, and had the same hair color and facial features. He was seeing another brother and sister pair, and they were sharing a bed, and as they got up, it became clear they were naked underneath the thin bedding.

That could never be us, Kyle thought, as the couple walked around their cottage naked, without any apparent reservations. The woman brewed a pot of coffee while the man used the bathroom, and then they both brought mugs of coffee out onto their deck. The two of them leaned against each other affectionately as they sipped their coffee and took in the morning light on the still water.

The man's hand reached around the woman's back, and he must have done something, tickled or squeezed her, by the way her back arched. Then they set their mugs aside and turned towards one another, pressing their naked bodies against each other, leaning into a slow, passionate kiss. Not a familial kiss. Very much something else.

Precum was dripping from the tip of Kyle's penis by now, but he didn't dare look away, and didn't want to finish himself off just yet, suspecting that something more tantalizing was yet to come.

The tall blond man guided his short sister back until her backside reached the deck table--the same kind that Kyle and Claire's cottage had--and then she scooted herself up onto it. They were in full sun, the binoculars giving Kyle a crisp view, as the man lined his erection up with his sister's slit. She had her legs spread wide, her whole body, her whole being was open to him, and Kyle saw her mouth open wide as he slid into her.

They started slow and gentle, and settled into a patient rhythm, of two people who have nothing in the world to care about except each other's body. Kyle was ready to climax, past ready, but by now, he wanted to see this through.

Then a dark, blurry shape moved in the foreground of his long-distance view, and it cut through his arousal too slowly for him to process, until he heard the sliding glass door opening.

"Shit shit shit," he muttered, scrambling for his shorts.

"Kyle! What the hell!" Claire said.

"Sorry," he sighed. Under his shorts, under the bedding he uselessly piled atop his crotch to obscure his erection, he was still aching with arousal. He was too close now, it would take forever to subside if he didn't just finish it off.

"Were you watching me?" Claire demanded.

"No!" Kyle said. "The other two." He pointed across the bay. "I know you said not to, but--"

"But you're still a teenage guy. Yeah, I'm getting that impression loud and clear," she said, and muttered something under her breath that sounded like "horn dog".

"Well, what are Ulrik and Vanessa up to now?"

She quickly grabbed for the discarded binoculars, as if to direct her gaze deliberately somewhere other than at her brother's pitiful attempt to hide what he'd been doing.

"You met them?" he asked.

"No, I just made up names for--oh," Claire stopped short. "Oh wow."

"What's happening?" Kyle asked.

He joined Claire by the glass door, but his eyesight was no match. At this distance he could barely tell that another cottage was out there.

"They're really going at it, huh," Claire said, forgetting her own propriety. Kyle noticed the way her mouth hung open, the way her breathing deepened. "It looks like any second now, she's about to--yup, here she comes."

It was torture for Kyle to only hear what was going on secondhand, from his sister's lips, and not be able to achieve his release.

"Can I just--" he began, reaching for the binoculars, but she batted his hand away.

"Oh, I think he's about to--did he just--inside her?"

Kyle couldn't take this anymore. He rushed into the bathroom and soon came all over his hand. It was a more copious load than he'd had lately, and it pooled there in the sink until he caught his breath and washed it down. He knew it might be obvious to Claire what he was doing, but it had to be better than painting the glass door with it.

When he came out of the bathroom, her face was flushed and desperate too, and she went in to take her shower with a distinct sense of urgency. So this is Claire aroused, he realized.

***

"In the past month, have you kissed Claire?" It was another researcher doing the evaluation this time.

"No," Kyle replied. "But she... uh... she kissed me once, just a peck on the cheek."

"Do you want to kiss her?"

Kyle clenched his jaw, and reminded himself to be open and honest. "No. Well, not her specifically. It's been a while since I kissed anyone, you know? Maybe if she can do it, it's okay if I do it too."

The two of them had been gradually rediscovering a casual level of physical affection that they'd lost sometime long ago, and Kyle actually appreciated it. Without it, it felt like he'd be touch-starved. Instead, it was just something more specific he was deficient in.

"Is Claire attractive?" The researcher sounded almost bored with him.

"Yes," Kyle said, trying to move it along.

"Have you felt attraction towards her?"

"I mean sure, but it doesn't mean anything," Kyle said. "She's the only woman in my life right now, and she is attractive, like I said. But feeling attraction doesn't have to mean anything else."

The researcher bent down over her notepad, taking notes. "Have you had any sexual contact with Claire?"

Kyle felt himself blushing, and he thought back to that time, both of them standing at the glass door, both of them aroused out of their minds. In retrospect, he recognized that it was a closer call than he'd like to admit.

"No," he said.

"Have you ever wanted--"

"No," he said again quickly, unwilling to entertain the thought, lest it lead somewhere he couldn't find his way back from.

MONTH 3

Even from underwater, Claire could hear the boat approaching, skimming over the water at high tide, when the path to the office was completely submerged.

It wasn't time for their monthly evaluation, and it wasn't time to restock the pantry, so she wondered what it could be. She climbed up onto the beach and let the seawater run off her body. She was feeling more fit than ever. If only she could take a selfie and post it for cred.

"Claire," the lifeguard from their first day greeted her. "Come join us."

Kyle was sitting in one deck chair, and Claire took the other, while the lifeguard stood.

"You guys have been here for two months already. Time flies, right? Well, we've collected a lot of valuable data in that time, but we need to adjust the experimental conditions periodically," he said. This had to be a speech he gave often, because he didn't stumble at all. "I just wanted to explain that, to help you understand why we're doing this."

"Doing what?" Claire asked.

"They took your bed," Kyle said.

"What? Why am I being punished?" Claire asked.

"It's not a punishment. This is an adjustment that some people don't have a problem with at all," the lifeguard said.

Claire thought about the couple--the siblings--across the bay, and it made her skin sensitive to think about what she'd seen them do. Ulrik, as she'd named him, had ejaculated deep inside his sister's vagina, in full view of the world, and Claire knew that sister couldn't have been on birth control. Of course those two would have no problem sharing a bed, but her and Kyle? She didn't want them to take any step towards that, no matter how small.

"No. I refuse," she said.

"Are you deciding to leave?" the lifeguard asked, and the question had a weight to it. Final answer?

Kyle looked at her, his disappointment clear on his face. He hadn't said so, but clearly he didn't have as much a problem with this as she did. Maybe just because they took her bed rather than his.

Yes, this change was inconvenient, but she found that she didn't want to end it over this.

"Whatever," she said with a sigh. "We'll figure something out."

That night, when the cottage was only illuminated by one lamp's golden glow, Claire was still conflicted about how to deal with this.

"A gentleman would give up his bed for the lady," she said, only half in jest.

"It's still my bed," Kyle said stubbornly. "Claire, I've been wearing clothes to bed this entire time. We can split the bed, it's not a problem."

She thought of the erection that her brother seemed to wake up with every single morning. Maybe he thought it was subtle underneath his shorts, but it was anything but.

"I'll sleep on the floor for now," she said. "It's fine. It's warm enough in here anyway."

"Alright," Kyle said, and when she was settled in, he switched off the lamp.

Except Claire hadn't accounted for how the bedding had kept her warm, and how low the temperature got overnight. In the middle of the night, the floor tiles were cool, and that chill soaked through her. She had a rough night's sleep, and in the morning, a dip in the sea was the last thing she wanted. Her muscles felt stiff and sore from sleeping on a hard surface, with only some of her own clothes in between.

She spent the whole day exhausted, in a head-ache fog, taunted by Kyle's bed. All of the energy and health and peacefulness she had felt since they came here, it was all so fleeting. In the afternoon, when Kyle went out for a walk, Claire let herself nap briefly on the mattress.

While Kyle was still getting ready that evening, in the bathroom brushing his teeth, Claire slipped into the sheets.

Kyle came out and laughed.

"We have got to take turns," she said. "I can't sleep on the floor every night."

Except she wasn't big enough to take up the entire bed on her own. She'd left one flank undefended, and Kyle slipped in on that side. There was in fact room for both of them to lie down without even touching. But just barely.

"See? Not a problem," Kyle said.

"Okay, but you have to wear clothes at all times," she said. "And the moment this gets weird, I'm cutting off your penis."

"Huh. This is a side of you I haven't seen in a long time," he said. "Good night, Claire."

It was warm at first, with both of them under a single blanket, and Claire felt her skin prickle slightly with sweat. She wished she could take off a layer, but she didn't dare. And then finally the temperature came down, and she sank into a deep sleep.

After getting so little sleep the previous night, she cashed in that debt, and woke later than usual. As her brain transitioned out of dream, she could feel a body against the back of hers, and it reminded her of all the times she woke up with Greg spooning her.

Then she realized it was Kyle, but she was still reluctant to move. He didn't even have an arm around her, it was probably just an unconscious huddling for warmth and comfort, and she decided there was nothing wrong with that. Except she could feel a slender line of pressure against her backside. Once she realized what that had to be, she slipped out of the covers before Kyle could wake.

It was an awkward arrangement to be sure, but the entire situation here was. Claire decided she could cope with it. Maybe even get used to it. It was like getting a cheap room at an expensive hotel, she thought.

At their next psych eval, Dr. Flavius was back on duty.

"Claire. How are you feeling?"

"Overall, I'm fine. I'm great."

"In the past month, have you and Kyle kissed?" he asked.

"We did," she said. After she started giving him a peck on the cheek, Kyle had started doing the same to her. And then, there was a time when they both intended to do that, and their lips met, briefly.

"It's been different since we had to start sharing a bed," she added.

"How has that been going?" the doctor asked.

"It was a real source of tension at first, but we're comfortable with it now. I am, anyway. It's not that big of a deal I guess, I just had to get used to it."

"Do you find yourself attracted to Kyle?"

"No," she said, but then she thought about waking up with him pressed against her back. She wished her body didn't have a pavlovian response to that feeling. "Not to him. Just... generally."

"Have you had any sexual contact with him?"

"No," she said. Not unless you count feeling his erection against the small of your back, through multiple layers of clothing. She hoped Kyle wouldn't answer the question differently.

"Have you wanted to?" Dr. Flavius asked.

The question was harder to reckon with than before. Ever since they arrived, she'd been discretely satisfying herself as best she could, but she knew from experience that there was so much she was missing out on, even if she was committed to never going back to Greg for it. She thought about Ulrik and Vanessa, and the utterly careless depths of their depravity. But that wasn't her and Kyle. There was no indication that they would ever end up like that, no matter how stir crazy Claire felt once in a while.

"No," she said.

"In the past month, have you menstruated?" the doctor asked.

"Yeah," she said. "It hasn't been like this since I went on the pill, but... it's fine, I guess."

"Good to hear. Any other requests?"

"A second bed perhaps?" Claire joked, and Dr. Flavius gave her an indulgent smile. They clearly weren't going to budge on that now. "No, nothing else."

MONTH 4

They were sitting down to dinner together, of the best pizza on their little island. Kyle cleared his throat. "Could you pass the iced tea,... hon?"

It came out so awkwardly that he blushed.

Claire gave a snorting laugh. "Hon!" she imitated. It sounded like a French stereotype. "They gave you the same homework?"

"Yup," he said, laughing. Dr. Flavius had suggested they stop referring to each other as bro and sis, and use terms of endearment instead.

"Hon!" became a recurring joke between the two of them. Sometimes it'd sound more like the honk of a goose.

But Kyle found it maybe having the intended effect on him. Once in a while, like a trick of the light, he would look towards his sister and see someone else there instead. Someone beautiful who looked just like her. Someone who, improbably, loved him just as much as Claire did. Especially when she came in from a swim and was drying her hair.

It would take his breath away for a moment until he remembered himself. Except, it became easier every time, to imagine he was living alone with a strikingly beautiful stranger, to let that fantasy linger a little longer before he shooed it away. It surprised him sometimes, what an amiable routine they'd settled into, after all the turf wars of their youth.

He'd wake up next to her and snuggle up to her back, even kiss the back of her neck, before realizing it was her. The odd thing was, this wasn't a learned behavior. None of his partners had ever invited him to stay the night. Kyle made a point not to let his fantasies run wild whenever he was conscious enough to recognize them for what they were.

On days like this, he'd get up early and make coffee, giving his hands something neutral to do, giving his morning wood a chance to soften before Claire woke up.

Suddenly there was a knock at the door of the cottage. Kyle went to answer it, as Claire sat up, still groggy.

It was that guy from their first day. Kyle had thought of him as a lifeguard at first, but he was clearly more than that. An enforcer of the institute's rules, it seemed.

"Good morning, lovebirds," he said with irony. "Doesn't look like I'm interrupting, at least. I'm hear for your clothes."

"Sure, here you go," Kyle said, handing over his duffel full of dirty laundry.

The lifeguard quickly transferred Kyle's clothes to a canvas bag. Since Claire was still waking up, Kyle brought her things over, too. It all went into the one sack.

"Those too," the lifeguard said, pointing up and down Kyle's body.

"No thanks. I'm good," Kyle said.

The tall, stocky lifeguard stood with his hands on his hips. "I'm sorry, but this is part of the experimental protocol. I'm here to collect all your clothes."

"What??" Claire said. "You can't."

The man sighed. "If you want to leave, you can leave any time. But while you're here, you agreed to participate in this study and follow all instructions. That was very clear in the stipend agreement."

The siblings were dumbfounded, and torn.

"I'll wait outside while you decide," the enforcer said. "If it makes you feel better, I've seen all kinds of people in the nude. It's really no big deal. Heck, I'll strip too, if it makes it easier for you." Then he closed the door.

"Do you think he's coming on to us?" Kyle asked.

"Us??" Claire asked, taken aback at the mere suggestion of a threesome involving Kyle.

"Look, this is messed up, and if you don't want to do it, I won't either. I feel like a frog in boiling water. First the bed thing, now this..."

"It's been an entire month since they took my bed," Claire said. "Besides, this has been messed up from the start. It's like... a fundamental aspect of what they're doing here."

Kyle didn't know what to make of that. He tried hard not to look at her while they discussed this. He didn't want her to notice his gaze lingering on her.

"Well, I guess... I'm willing to continue this if you are." Kyle said, making up his mind even as he said it.

"It is a lot of money," she said. "We just... need to be careful about where this leads."

"It doesn't have to lead anywhere," Kyle said. "Things haven't gotten weird between us yet, have they?"

"Not yet," Claire admitted. "Alright. Just... turn away for now, okay?"

Kyle looked out over the bay, towards that other cottage in the distance, with that other couple. He couldn't make them out with the naked eye. He used to they were nudists, but now he wasn't sure. They were certainly exhibitionists, at least. There was no other reason to fuck out on the picnic table.

Rather than wait his turn to undress, Kyle pulled off the shirt and loose pants he wore as pajamas.

"Here," Claire said, and Kyle turned, keeping his bunched-up clothes self-consciously over his crotch as he grabbed hers from her. Then he turned back towards the door, and slid it open, offering both sets to the man outside, who stuffed those into the sack and briskly walked away.

"Coffee?" Kyle asked, but Claire slipped past him towards the door. He tried not to measure the distance between their naked bodies. The closeness. Better to let hers be a motion blur in his vision.

"I'm going for a swim," she said.

Kyle lay down on the bed, letting his erection stiffen, like it wanted to the whole time. He could feel his every nerve ending growing more sensitive in anticipation of what ritually always came next, whenever he had the cottage to himself. He teased his shaft with a light touch, encouraging its awakening, but not rushing himself.

He was conflicted over what to lure his mind to climax with. Surely not his sister. Surely not the beautiful stranger he sometimes imagined she was. But it was her naked body, even quickly, furtively glimpsed, that he kept coming back to.

Then abruptly, the sound of the sliding door startled him out of his fantasy before he was even close to his finish. He grabbed the bedsheet and pulled it up over himself, rolling to the side so it wouldn't make an obvious tent as Claire came back in.

She was at her most alluring like this, he thought, as she grabbed a towel and started drying herself off. Kyle had never really noticed the curve of her breasts before, the thickness of her hips, the trail of wiry dark hair down to where her legs met.

This wasn't helping at all with his unsatisfied arousal. It was only because she was deliberately avoiding looking at him that he could get away with sneaking a glance at her. But he couldn't keep doing this. He couldn't let it drive him mad.

"That was quick," he remarked.

"I got hungry," she explained.

"I'm just gonna... go for a walk," he said, and slipped out, keeping his body carefully angled away from her.

The tide was relatively high, the sand damp and spongy under his feet. It felt odd to be out on the beach completely naked, with his erection swinging free in front of him, even with no one around.

He walked to the end of their little domain, where the line of sand dipped down into the lapping waves, and wondered what to do. He considered jacking off right there, letting his semen spill into the sea. Maybe lying down and humping the sand. The thought made him sad. He knew how limited the pleasure available to him out here was, compared to what he'd found in a woman's touch, and in a woman's body. Not Claire's though. Never Claire's.

Eventually his erection subsided on its own, at least for the moment. He'd need to relieve it soon. He arrived back at the cottage surprisingly winded from pacing the beach. What he noticed about Claire now was the strength of her muscles. Kyle realized he'd been letting himself go, while they'd been there, and decided to get up and go swimming with her in the morning.

***

Claire awoke to the pressure of Kyle's penis against her backside, but nowadays there were no modest layers of cloth between them. She'd woken up with men spooning her before, but she knew it wasn't right to have this kind of contact with her brother, so she slipped out of the bed.

There was no bathing suit to put on, so she just drank a glass of water before going to the door.

"Wait up," Kyle said, sitting up in bed. "I'll come swimming with you."

She turned towards him, unthinkingly. Fortunately he still had a sheet over his lower half, but even so, it wasn't subtle. He'd had an erection yesterday morning too. And yesterday afternoon. And last night. More often than not, it seemed.

Claire searched her brother's face, looking for an ulterior motive, finding none. She was privately a little impressed. "Oh. Okay. Let's go."

She led him down to the water and out into the shallow bay, not daring to look back. From behind her, she could hear his gasp when the cool water reached his sensitive parts, and she smirked.

He matched her stroke for stroke, keeping up with her for distance. His height advantage made up for his poorer technique. And he never got too close for comfort.

The exercise and the chilly water seemed to clear his mind, at least from what Claire could tell from a glance at his waist.

They got back to the cottage and toweled off, but Kyle kept his towel on throughout the morning, though the topography of it was clear. As soon as he got warm and dry again, his erection returned.

"We can't use towels as clothes," Claire said. "Or they won't let us keep towels."

"You don't know that," Kyle said, before conceding her point. "Fine."

"Is it always... like that?" she asked.

"Do you really want to know?"

She shook her head. If her brother was secretly always hard under his sweatpants, she didn't need to know that. They just needed to get through this, and back to a world where they could hide these things from each other.

At the same time, his response told her that he hadn't noticed her own persistent arousal. The way her nipples were always pulling at the taut skin of her breasts. The way she left a smear wherever she sat too long.

Claire tried to ignore her brother's erection. It didn't seem like he meant to be subjecting her to it, even if it felt like she was taking psychic damage from being in the room with it. Wounds that didn't even give her the warning of pain.

But it went on so long that a drop of precum started making its way down his shaft as he prepared dinner.

"You're... uh... leaking," she said.

"It's not piss," he said defensively.

"I know what precum is, dork," she said. "I have had sex before."

"Okay, well, there is one way to deal with it, but you might not like it," he said. She braced for the worst. Instead, he went over to the bathroom and shut himself in. Even with a wall between them, there was no secret about what he was doing in there.

Claire sighed. She thought he'd been doing that already.

Relieving himself did solve the problem of Kyle's erection, at least for part of the day. And Claire found that while he was in there, obviously occupied, she could finally attend to herself properly.

The next morning, he finished quickly, and stepped out of the bathroom while Claire was still rubbing her clit. So very close, but not quite close enough. She yelped and pulled the sheet up over herself.

"So you get to get off, but I don't?" she asked, outraged.

"Sorry, I didn't realize," he said, and stormed out of the cottage in a hurry.

She got up and went into the bathroom to finish herself off, closing the door behind her in case Kyle came back before she was done. Her pulse was racing, but her orgasm wasn't as near at hand as it had been.

In the sink, she found a pool of milky white fluid. He'd forgotten to rinse it down. With one hand between her legs, she brought her other hand, trembling, to her brother's semen. It was still warm.

She had an inappropriate, inexplicable urge to push those fingers, coated with her own brother's semen, down into her cleft, into herself.

It had been so long since she'd had a man's cum inside her. When she was on the pill, it was just a thing that happened. A momentary pleasurable sensation, nothing more. Icing on the cake, as it were. Now it was something she felt primally drawn to.

Her hand shook violently, her breath turning to gasps, as the long-awaited orgasm crashed through her. As she caught her breath, she brought those seed-coated fingers to her lips and sucked them clean. Then she washed his load down the sink. Yes, she'd had an impure thought about him, but he would never need to know.

***

Kyle awoke slowly, not registering at first that this time, for once, his erection wasn't achingly mashed against the small of Claire's back. Instead, it had somehow slipped between the backs of her thighs. Whether it was lubricated by her juices or his, he didn't want to fathom. Now he could feel the tip of his penis nudging against something soft and wet and hot.

He bit his lip, hoping to persuade his swelling to subside. Claire's breathing was soft and even, but Kyle didn't want to be caught in this position, in which she might assume he'd put himself intentionally. He started to pull back, his shaft gliding along her sopping, sensitive flesh, and suddenly her hips shifted, pushing her buttocks back against his stomach. With the change of angle, he felt the tip of his cock slip just barely into her.

He froze again, shutting his eyes to feign sleep if he had to. He could feel the heat and pressure of her squeezing down on him, enveloping him. His instincts were begging him to thrust forward, to push more of himself into her, and it was a white-knuckled struggle to resist. But she didn't shift again, didn't lift her head. Her breathing settled back into its deep, slow waves. As soon as he could, or so he told himself, he withdrew from her. In her sleep, Claire mewled softly at the loss of him inside her.

Kyle couldn't get back to sleep after that, and eventually got up and stroked himself to completion in the bathroom.

His mind was clouded all day with the recollection of that moment. That brief taste of what it was like to be inside his sister. He found himself getting hard, staying hard, weeping precum, having to avoid meeting her gaze. But eventually he managed to move past it, until it almost felt like it didn't really happen.

Kyle sat down in front of the webcam, scooting the chair close so that the camera wouldn't show him below the waist.

"Have you had any sexual contact with Claire?" the person on the other end was asking, and Kyle was so distracted he didn't even think of censoring himself.

"Yes. I... I penetrated her once," he said. "While she was asleep. I didn't mean to. I feel like shit about it."

He knew he should feel like shit over it, and he had an unresolved mass of worry in his stomach, and he assumed the two were related.

The person on the other end finished taking notes, and flipped through a big binder on their desk. "Do you find yourself desiring more sexual contact with her?"

"Yeah," Kyle admitted. "I do, I guess. I won't, I never would, but... I can't deny wanting it. God, I want it so much."

"Thank you, Kyle. Please bring Claire in next."

***

"Do you find Kyle attractive?" the researcher asked Claire.

"Yeah," she said, and then blushed. "I mean, he's my brother, but I admit, he's... well, he's gotten pretty fit, and--"

"I get the gist," the researcher said. "In the past month, have you had any sexual contact with him?"

"No," Claire said, shaking her head. "Nothing like that."

"Have you wanted to?"

"Okay, this is going to sound weird, but... this morning I had, like, a really intense sex dream. There was a man pushing into me from behind, and I was pushing back, and partway through this dream, I realized it was him, but... I didn't want to stop. And I don't know what that says about me. I don't want to have sex with my... Kyle... I don't even want to be dreaming about him, but... it was so hot, the hottest thing I've felt in months."

"In the past month, have you menstruated?"

"Um, yeah," she said. "It was a little awkward with the whole nudist thing, but nothing I can't handle occasionally."

MONTH 5

The next month passed quickly. They got used to giving each other enough private time to satisfy themselves, even though Claire was a bit shocked at how often Kyle ended up jacking off. She'd come back to the cottage, and like clockwork, he'd start stiffening up again before long.

Sometimes she wondered if he'd be better able to manage himself if he had access to a bit of porn. Maybe she would be better off with a little porn too. The paperback romance novels had their moments, but it was all couched in flowery euphemisms.

So, out of necessity, they got better at ignoring each other's state of arousal, even if it sometimes put a damper on their affection sometimes. She'd lean in to kiss him and find a barrier erected between them. Sometimes she'd even end up with a smear of his precum on her skin, which she got used to wiping off without a second thought. Fish all pee in the ocean anyway, she thought. If she was going swimming every day, she could hardly linger on it too much.

Her mind as only half there as she answered the routine evaluation questions. Yes, she was still ovulating. No, they had not had sex.

The researcher finished taking notes and put down their pen. "One more item on the agenda today. Would you bring your brother back into the room, please?"

"Sure," Claire said, and got up to open the door. "Hey. They want both of us."

"Okay," Kyle said, confused, and followed her back into the cottage.

"Alright. You two are doing very well, but there's something that we need you to do, at this point in the experiment. We need you two to have genital contact."

"But we already did!" Kyle objected.

At the same time, Claire was objecting, "You can't make us do that!"

"This is a standard part of the protocol at the six month mark. Testing how you respond to this stimulus is an important part of the experiment. You are, of course, not being forced into anything, and you can leave at any time."

"You can't make me fuck my brother," Claire said anyway.

"You will not be having intercourse," the researcher patiently explained. "This is a standardized procedure that I'll walk you through step by step."

"Well," Claire began, but she felt a little of her outrage ebb. They were already living in the nude together, sharing a bed. They'd already ceded so much ground that this didn't seem like all that much more. "We need a moment to discuss this first."

"Are you actually considering doing this?" Kyle asked.

"It's... whatever," Claire said. "We do this, we check this box, and then... we don't ever have to talk about it ever again."

"I don't know," Kyle said. "I thought this was about testing whether incest occurs naturally, and now they're pressuring us into--"

"It doesn't have to be a sexual thing," Claire said. "Just skin against skin. No big deal."

She realized that she might be more desensitized to this from all the OBGYN exams involved in growing up female.

"Okay. Yeah. Just skin against skin," Kyle repeated.

"We're ready to proceed," Claire told the webcam.

"Let's have Claire lie down on the table," the researcher said, hunching over their monitor to get a clear view. "Now, spread your legs wide."

The table's surface was cool under Claire's back, but her whole body was on fire. She wondered how obvious it would be to Kyle that she was practically gushing with arousal right now, with her legs spread wide, her pussy angled up for the looking, for the taking. They said no intercourse, but that would only remain true if everyone involved kept their heads on straight. She longed to touch herself, to part herself, to probe herself.

"Now Kyle, you step to the edge of the table, please. I need you to just rest your penis on top of Claire's vulva, and I'm going to start a timer for one minute."

Claire felt Kyle's thighs press against hers, pushing her legs wider, and then the meaty weight of his erection laid on her slit, right where her lips were naturally parted to receive a mate. She longed for any kind of movement, any kind of friction between them, but Kyle stood still.

"See? Nothing to it," he said. A joke, or a willful self-deception.

The heat of his erection amplified her own. She could feel herself getting damper against him, and if there was any doubt about whether he could feel it, she got her answer in the way his shaft pulsed with pleasure. She looked down and saw a drip of clear precum slide from the tip down into her folds. It could be carrying sperm, she knew, and she hated the way that fed back into her barely restrained passion.

She was breathing heavier now, just from this barest of contact. If it went on much longer, it would make demands of her that she wasn't ready to fulfill. If she was to climax like this, it would expose her blaze attitude for the sham it was. Knowing that didn't help stave it off.

Without daring to look at where they were in genital contact, Claire could feel him growing hotter, fuller, more engorged with every passing second. It's not me he's attracted to, she reminded herself. He's just a teenage guy with a libido running rampant. Any naked woman will do. Any vagina against his cock would have this effect on him.

But his shaft would feel so good sliding against her slick lips--no. She blinked, trying to clear the thought from her mind. This was still Kyle resting upon her. Her own brother.

The timer went off, and Kyle backed away, taking a deep breath. Claire let her tension collapse onto the table, and the video call wrapped up.

MONTH 6

That night, Claire asked, "When they first suggested it, what did you mean, we already had?"

Kyle looked like a deer in headlights. "There was a morning, like a month ago, when I woke up, and I was... inside you."

Claire's breath caught. Shit. She immediately had so many questions, so many worries. "How far did it go?"

"Just the tip," Kyle said, and then realized what she was asking. "I pulled out as soon as I realized. It only lasted a moment. It... nothing got inside you, if that's what you mean."

"Except the clear stuff you're always oozing," she said, though his words did offer some relief. At the same time, the thought crossed her mind that she had missed it. A jealousy she knew she shouldn't have, and a curiosity she must not indulge, but...

After a moment, she worked up the courage again. "Can you... just put it on me again?"

No questions asked, Kyle got up and knelt between her legs on the bed. It would have been so easy for him to just guide himself inside her, and that was certainly what her body wanted most, but instead, he rested himself on her slit again.

"Is that good?" he asked.

Claire reached down and ran a fingertip around her clit. The motion of her finger pulled at the delicate, sopping-wet skin that was touching him, and she heard him gasp in time with herself. Her pussy was squeezing, gushing in time with the flow of precum down into her slit, a risk that she both could and could not deny. She looked up into his eyes, and his gaze met hers, taking her in, all of her nudity bared to him, and his admiring gaze, its forbidden thrill unspeakable, drove her to greater heights.

She fingered herself patiently, drawing out this moment instead of hurrying it along. Perhaps they were crossing a line, but hardly more than they already had. She could feel him firming up further against her, the muscles of his rod twitching occasionally with barely restrained pleasure. His intoxication fed into her own. His restraint--it seemed superhuman to her that he wasn't pushing this further--kept her from having to either give in to a forbidden desire or bring this at to a premature close.

Soon she was reaching her precipice, a strangled cry escaping her throat as she started to shake. Then to her surprise, he swelled full, the skin of his tip growing momentarily red and taut, and then his semen shot out across her stomach, his orgasm hot and wet against her skin. He pushed his shaft forward just enough that the tip was past her slit, so that none of the semen that poured out of him would end up flowing down into her.

Claire got up and showered the evidence off of her body. She worried that she had broken their relationship now, but when morning came, it was like nothing changed. Kyle had an erection again that he was still sheepish about her seeing.

It was hard for her to ask for it the first time, but soon it became just a thing they did occasionally, when masturbating alone wasn't getting her off. This not-quite-sex-exactly thing. This flimsy veneer of plausible deniability.

Whenever it took hold of them, they were in its thrall, and otherwise, it felt like a separate reality. A separate dimension. An entirely implausible one, since they were, of course, still normal siblings.

One night the clinical "genital contact"--not intercourse, not at all--wasn't quite enough anymore. The forbidden-ness of it was all worn out.

Claire's heart was in her throat as she asked, "I want--you can--can you... just put it inside me?"

"Yeah, sure," Kyle replied, as if he was passing her the salt shaker.

He slipped his erection from her slit just long enough to line it up with her hole, and started pressing it into her. With every millimeter, she knew they were crossing a line that couldn't be uncrossed, but that just elicited a fresh wave of new sensation. Oh, how she'd missed this, and how absurdly perfectly he fit into her. She couldn't recall it ever feeling quite like this for her before.

Then he was in her, fully inside her, and he just stopped, leaving it there, just like he was supposed to. If laying it atop her had been enough for him before, this was a bounty of new sensations.

"I need you to pull it out if you..." she said. "I'm not on birth control." She felt him jerk inside her at that. It made her gasp. "Seriously, Kyle."

"Yes. I hear you. Loud and clear," he said. "That wasn't about what you were saying about birth control." He made himself jerk inside her again, this time clearly as a joke, but one that took the breath out of her again. She knew how his precum always poured out of him whenever his cock flexed like that.

It didn't take her long to finger herself to a climax with him inside her, firm and twitching and achingly sensitive.

"Oh fuck," she gasped as it rolled through her. She could feel herself clenching squeezing down on him.

His grunts of pleasure were distant to her ears until he said, "Claire, I'm about to--"

He pulled out and fountained all over his hand. His withdrawal felt like one bitter note alongside the lingering sweetness of her pleasure.

"Did... did any of it get inside--?" she started to ask.

"No," he said, with absolute knowledge he couldn't possibly have. It weighed on her later, when she tried to sleep.

The next morning, he was making coffee when she got up. She felt a closeness, an affection for him, of a different sort than they had before. She put a hand on the small of his back, and noticed how his cock sprung to life. There was no denying it now, no pretending that his hardness was just natural, or automatic, or had nothing to do with her, and the pleasure that her body gave him. It was a sign of his longing, his longing for her specifically.

"Kyle, are we... still sane?" she asked.

"Yeah," he said. "Well, most of the time."

She searched his eyes for some remnant of the old relationship they used to have. But it was still a surprise when he leaned in and pressed his lips to hers, not in a quick peck, but in a passionate kiss. A kiss that could carry her to bed, rip off all the clothes she wasn't wearing, and ravage her just the way she needed it most. A kiss she couldn't afford to have.

She pushed off his chest. "Sorry, I have to go."

She ran along the beach at full speed, trying to purge these urges from her blood, making her heart pound for a reason that isn't her brother's touch. When she got it out, she felt calmer, grounded, resolved.

He was on the bed when she returned, lazily fondling himself. Masturbation wasn't the main attraction anymore though. And the mechanics of his sexuality were no secret from her now, so he didn't move to hide it like before.

She climbed the bed, straddled his lap. Instead of guiding him into her, like she wanted the most, she reached down and pressed his shaft to her slit, and started to rise and fall, gliding him along her lips. This was in some ways less of a transgression than the night before--she wasn't taking him inside her, no matter how much she longed to--but it was something more than they'd done together, because of the way they moved as one, grinding their parts together, towards a shared bliss.

He managed to hold out long enough for her to reach her climax first. She couldn't hold it back and didn't want to, screaming for the cottage walls to hear, screaming for anyone across the bay to hear, if it was loud enough to carry that far. Then he thrusted up, urgently, the tip aiming back at himself in this position, and his semen hit his chest.

She wanted to kiss him then. Still wanted to take that cock--still pouring out semen--deep into herself. But instead she rolled off him and collapsed.

A thought occurred to her. "You're not--you weren't a virgin, were you?"

"No. Gosh no," he said with a laugh.

"Good. I didn't think so..." she said. But the thought reminded her that she was five years older than him, and he was still a teenager. Legal, but not by enough.

"Kyle, we need to stop," she said. To her relief, he didn't immediately object. "Before we do some permanent damage."

Kyle let out a deep breath. "Are you sure we aren't there already?"

"We haven't even been here all that long," she said, trying to measure the time. It was so easy to lose track. "We have so much longer yet to go. If we put a stop to this now, maybe we can kind of... detox."

It took a while for him to respond. "Sure, I'll go to detox with you."

"You don't 'go to' detox," she teased. "You mean rehab?"

"Whatever."

Over the rest of the month, they were able, at least for a little while, to pretend like nothing had changed between them. Like they were the same siblings they were when they arrived.

At the next psych eval, it was Dr. Flavius asking the questions.

"Have you had sexual contact with Kyle?" he asked.

"Yes. Five times," she said, feeling ashamed of it.

"Intercourse?" he asked, as if it was smalltalk.

"Outercourse, mostly," she replied. "Penetration just once."

"Do you intend to continue having sex with him?"

"No," she said, a little taken aback by his choice of words. They hadn't called it sex when it was the research staff directing them like actors on a stage, and most of what they'd done alone had been just the same. Well, it had led to more, just like they probably hypothesized that it would. "We shouldn't. We can't. And... it doesn't matter anyway, because we failed the whole test. Anyway, now that we've failed the test, or passed it, or whatever, I'm guessing your done with us, right?"

"No, no," the doctor said with a frown. "This is a year-long experiment, and we will be tracking the progression of your relationship throughout. Are you still menstruating?"

"Yes, I got my period a week after the... uh... penetration," she said.

"Do you need a pregnancy test sent over?"

"No, I don't need one right now, but... about birth control--" She hated that it had become an issue again now, but she had to ask.

"I'm sorry, Claire. It's not allowed, under the experimental protocol," the doctor said with a forced smile. "Different forms of birth control, different effects it can have... it would introduce a lot of confounding factors..."

Claire nodded. "That makes sense, I guess. It's fine. I'll be fine without it. Sorry."

It had to be fine, if they were going to make it through this whole year without producing incestuous offspring. Which really shouldn't be a problem, she thought. Her constant, elevated libido, her unnatural, unwanted attraction to Kyle's body, these were things she could handle. Things that might pass on their own, if she just could just keep herself from fixating on them.

As the video call ended, Claire wondered why this didn't feel settled for her, even knowing what she had to do. Why she was still nervous, trembling in her seat, about exactly how the second half of this year-long experiment might play out.