Siblings' Power Shift Pt. 01

Kai drove home from his shift at the local grill restaurant, driving slowly and a little below the speed limit. While most people would be excited, he certainly wasn't. Back at home--he likely had more work waiting for him.

He lived in a modest suburban home, a typical three-bedroom, one-bath setup that always felt a bit too small for his liking. But he didn't have to pay rent, so that was good. At 19, he was stuck between adolescence and adulthood, living under his parents' roof while working a part-time job at the local grill restaurant. His older sister Serena was 21, currently in her final year of college. She still lived at home too, saving money while she finished her nursing degree. They got along well most of the time but bickered here and there, as siblings do.

Their parents were devoutly Eastern Orthodox, strict about their beliefs and moral codes. Church every Sunday, prayers before meals, and absolutely no tolerance for anything they deemed inappropriate. That was the problem.

Kai could never forget the day his parents gave him and Serena 'the talk'. Their parents had just returned from a church retreat, looking more serious than usual. Kai's memory wasn't great in general, but one thing he'd always remember was his father's exact words:

"Masturbation is a sin. It's a temptation of the flesh meant to lead you away from God. Giving in to it weakens your spirit and damages your soul."

Despite the serious talk, Kai and Serena didn't fully buy into the teachings they were raised with. The very next day, when it was just the two of them at school, they voiced their doubts to each other.

"I don't get it," Serena had shrugged. "Why is it bad? Why is just being curious about... that kind of stuff... a sin?"

Kai was relieved to hear her say it. He had been wrestling with the same question too. "I know, right? It's like they're afraid that we'll turn evil if we partake. How can something that doesn't hurt anyone be so bad?"

They'd shared laughs over the contradictions and the loopholes they found in their parents' rigid rules. They were careful, though. Neither of them dared to admit how deep their doubts really went. They still played the part of obedient children, bowing their heads during prayers and attending church without complaint. But the faith their parents tried so hard to instill in them never quite settled in their hearts the way they intended.

Late one night, curiosity got the better of Kai, and he decided to experiment. Locking his bedroom door, he knew the temptation was too strong, and he had to give in.

Guilt followed immediately, and he half-expected his parents to burst into his room to confront him like a SWAT team raiding a house for narcotics. But nothing happened. He didn't feel corrupted or ruined. If anything, he felt normal.

Afterwards, masturbation became a secret habit. He was always careful, locking his door and double-checking that his parents were asleep or out of the house. He never spoke about it, not even to Serena. It was his deepest secret.

Then, a few weeks ago, Kai made a big mistake. Masturbation had become boring, and one day he made his way to the adult store in the mall, purchasing himself a Fleshlight and a bottle of lube. In his haste to hide them before anyone got home, he tossed the receipt in the kitchen trash bin, never imagining anyone would notice.

But Serena did.

She fished it out while cleaning up and confronted him the next day, a wicked grin across her face as she waved the crumpled evidence in his face.

"You know, Mom and Dad would lose it if they found out about this," Serena had teased, folding her arms smugly. "They might even disown you."

Kai's heart sank. He could already imagine his parents' reaction--the yelling, the disappointment, the endless lectures about sin and temptation. There was no way he could let that happen.

Since then, Serena had him wrapped around her finger. He was her personal servant, running errands, doing her chores, and even cleaning up after her. She was already a brat and got everything she wanted, but this took it to the next level. Kai grew resentful, his anger growing each time she ordered him around. He needed leverage, something to hold over her, but Serena was annoyingly careful. Her bedroom door was always locked when she wasn't around or whenever she was in the bathroom. Kai suspected she was hiding something, but he never had a chance to investigate.

Until today.

His shift at the restaurant was cut short when a fire broke out in the kitchen. Luckily nobody was hurt, but they had to close for the day.

When Kai finally pulled into the driveway and stepped inside, he heard the unmistakable sound of the shower running. His parents were out of town on a business trip, so it had to be Serena.

Kai's heart raced when he noticed her bedroom door was open ever so slightly. She must have been in a hurry, thinking she had the house to herself. This was his chance.

His pulse quickened as he slipped inside her room, the air tinged with the faint scent of her perfume. Her space was neat, obsessively organized, but he was determined to find something--anything--he could use against her. At first, there was nothing unusual: textbooks neatly stacked on her shelf, clothes folded in her closet, and her bed perfectly made.

Then he saw it. A pink object on her desk. He did a double-take, his eyes widening as he realized what it was. It was an adult toy, bold and unmistakable, lying out in the open. It was a sleek, pink, U-shaped silicone toy, compact in size with a power button. The remote was small and oval-shaped, matching the toy's pink color. It had a smooth, matte finish with simple buttons and a discreet LED indicator.

Shocked, Kai's lips curled into a grin. He wasn't expecting this. This was his ticket out of being Serena's personal servant.

He couldn't help but grab the remote and press the button to test it out. The toy jolted to life instantly, vibrating intensely and skidding across her desk. He quickly turned it back off and positioned the toy back where it had been, thankful that it was clean. Although they had both agreed that masturbation wasn't as big of a deal as their parents made it to be, Kai never would have imagined that Serena would go so far as to buy a toy to pleasure herself with.

Kai ruffled through her trash can for a receipt, but he found nothing. Then he checked her desk drawer, and tucked away underneath a notebook were two wrinkled receipts. Kai carefully smoothed out the wrinkles from both as he read the details. One was Serena's receipt. The same adult store at the mall, but purchased about a month before Kai bought his stuff. The other receipt was his own--the one that granted Serena the power to use him as her slave. He couldn't believe his luck. Serena's blackmail was officially over. With both receipts in hand, Kai knew the power dynamic had completely shifted.

But then a wicked idea crossed his mind. He looked up the toy online and found out that a remote control could be purchased separately. And conveniently, the adult store in the mall had one in stock. He decided to take it a step further. He popped the battery out of Serena's remote and made sure everything else was exactly as it was before--with the exception of the two receipts, which he pocketed. He knew he had enough time to buy another remote because Serena took notoriously long showers when she had the house to herself.

Kai drove to the mall, speeding, and his adrenaline made the trip feel like a Fast and Furious race. The cashier barely glanced at him as he made his purchase, his heart pounding as he clutched the bag on the way back home. Now, standing in the hallway with his new remote, he heard the hair dryer shut off. He needed to be careful and play his new cards right.

He slipped into his own room, closed the door, and sat on his bed, staring at the remote. His mind raced with possibilities. This was his chance to turn the tables, to make Serena pay for every chore, every errand, and every smug look she had given him while holding that receipt over his head. But he had to be smart. Doing research, he discovered how the remote's sole button worked. It was rather simple. An initial press turned the vibrator on, starting it on level 1, which was the lowest setting. Subsequent presses would increase the level to a maximum of level 10. During any level, pressing and holding the button would turn the device off.

Kai carefully deposited the remote into his pocket, his grin widening. Payback was going to be sweet. But how was he going to get his sister to use the vibrator? And how would he know when she had it in? It wasn't like he could just casually ask her.

Kai stepped into the hallway and approached Serena's bedroom door, knocking loudly and trying to keep his expression casual. He heard her shuffling around before the door cracked open, revealing her damp hair tangled around her shoulders. Her eyes widened in surprise. "Kai? You're home? Already?"

Kai shrugged, leaning against the doorframe. "There was a fire in the kitchen. They sent everyone home early. Nothing big, just some grease flames."

He watched her face closely, enjoying the way she struggled to compose herself. Clearly, she hadn't expected him to be here.

As she opened the door wider, Kai's eyes flicked over to her desk. The pink toy was gone. He fought back a grin. He knew exactly where it was now.

"Oh... well, I'm glad you're okay." Serena hesitated, biting her lip before asking, "Hey, do we have any 2032 batteries at home? You know, those little coin-shaped ones?"

Kai felt a jolt of satisfaction. She was already looking for a replacement, and he knew exactly why. But he kept his expression neutral, tilting his head in curiosity. "What for?"

"Uh... my computer mouse died." Serena's eyes widened just for a second.

"Your computer mouse? You mean the wired one?" Kai's grin widened, and he scoffed. He pointed toward her desk, where the black cord of her mouse was clearly visible, tangled behind her laptop.

Serena's cheeks flushed. Her fingers twitched at her sides, the faintest sign of her growing impatience. "Just... do we have any or not?" she snapped, her voice sharp.

Kai shook his head, pretending to think. "Nope, doubt it. Last time I checked the garage, there were only AA and AAA batteries."

Serena's shoulders sagged, her frustration poorly concealed. "Fine. Whatever." She turned on her heel, slamming the door shut behind her.

Kai stood there for a moment, the thrill of victory surging through him. He had never seen her look so flustered. He could almost hear the gears turning in her head as she tried to figure out what went wrong. What she didn't know was that he was many steps ahead.

He turned and walked back to his room, the remote feeling heavier in his pocket. He flopped down on his bed, pulling the small device out again. He leaned back against his pillows, grinning to himself. Serena had no idea what was coming.

Kai decided not to waste his half-day off and sprawled out on the living room couch, feet kicked up on the coffee table, watching the newest episode of his favorite TV series. Serena's bedroom door creaked open moments later, and he fought to keep the smirk off his face as she came into view, dressed in a baggy hoodie and tight black leggings, her hair tied up in a messy bun.

She was heading out. Of course she was. Probably going to get that battery she needed. Kai kept his eyes on the TV but spoke up just as she was about to put on her shoes. "Where are you off to?"

Serena paused. "Grocery shopping," she answered, avoiding his gaze.

"Oh? You sure you're not going to buy batteries for your wired mouse?" Kai couldn't help but take another jab at her.

"Shut up, Kai." Serena's face twisted in annoyance as she bent down to pull on her sneakers, fingers moving quickly as if she couldn't get out of the house fast enough.

Kai watched her for a moment, then lazily stretched his arms over his head. "Hey, before you go, make me some microwave popcorn."

Serena stopped tying her laces and turned to glare at him. "You have legs, don't you? Make it yourself."

"I could... but I think you'd regret not doing it for me." Kai's smile didn't waver.

Serena stood back up, eyes narrowed, her head tilting as she looked at him like he'd lost his mind. "I think you're forgetting who's in charge here. I'm the one with dirt on you, remember? You don't get to make any demands."

Kai slowly reached into his pocket, his fingers curling around the cool plastic of the remote. He looked her dead in the eye, his grin widening.

"Oh, really?" Kai asked, his voice calm, almost playful. "But things change, sis."

He pressed the button.

Serena's eyes went wide, and her body jolted as she let out a surprised squeak. She instantly squeezed her legs together, her knees buckling, and she had to hold on to the wall to steady herself. A confused gasp escaped her lips, her eyes wild with panic.

Kai watched her with amusement, his thumb hovering over the remote's button. "Something wrong, Serena?"

Her mouth opened, but no sound came out at first. Her fingers trembled as she relied on the wall for support. "What... did you do...?"

Kai leaned back on the couch, looking completely relaxed. "Nothing," he said innocently, his eyes gleaming with mischief. "I just asked for some popcorn."

Slowly, deliberately, Kai reached into his pocket and pulled out the pink remote, holding it up in the air for her to see. The color drained from Serena's face as her eyes locked onto the remote, recognition dawning instantly. Her mouth fell open in horror. "You... you didn't..."

Kai's smirk was wicked. "I sure did."

"How did you even... know about...?" Serena started, her words choking in her throat.

"Your room was open," Kai shrugged. "And there it was, chilling on your desk. I had to capitalize."

"Why... would you do that?" Serena seethed. Her legs wobbled, and she nearly sank to the floor, her breaths coming out in short, uneven gasps. "That's an invasion of my privacy!"

"So?" Kai snorted.

"But the remote doesn't work," Serena gasped. "I double checked."

"This one's new, freshly purchased about 20 minutes ago." Kai then explained his whole plan and how he removed the battery from her remote. "That's how I gained the upper hand."

"This... this is so messed up." Serena couldn't believe what he had just done. "You hijacked my vibrator! Are you messed up in the head?"

"Maybe, maybe not," he replied casually. "But I do know that if you don't want me to continue adding levels, you'd better be quick with that popcorn."

Serena hissed, sprinting towards her brother, desperate to reclaim control of the remote. Kai immediately pressed the button two more times. The new shock of power sent her straight to her knees.

"You thought I was bluffing?" Kai snorted. "Now hurry up with that popcorn."

Serena's eyes widened, a shudder running through her as she winced. "Y-you... bitch! Well, turn it off first! I can't even stand up!"

Kai considered her demand, pretending to mull it over. "Fair enough." He held the button again, and Serena's whole body sagged with relief. She took a deep breath, steadying herself before turning away and stumbling toward the kitchen. She trembled slightly as she pulled a bag of popcorn from the cupboard. The microwave beeped as she set the timer, the hum filling the awkward silence.

As the kernels popped, Serena leaned against the counter, her face still flushed. She looked over her shoulder, her eyes glaring daggers at him. "I'm your sister, Kai. You can't do this to me."

"Oh, really?" Kai leaned back, propping his feet up on the coffee table again. "You've been a little brat to me for weeks. Blackmailing me and making me do everything for you. I'm sick of it! But now..." He held up the remote and grinned. "Now the tables have turned."

"But we're family," Serena argued. "We're supposed to always have each other's backs."

"Did you have my back when you forced me to drive you and your stupid friends to the mall?" Kai demanded. "You knew I had a date that day, and you forced me to cancel!"

"It's not like she wanted you anyway," Serena huffed before regretting her words, her eyes widening with terror. "Sorry! I didn't mean that!"

Kai noticed how terrified his older sister had looked. It was a sight he had never seen before, and it made him feel... powerful. After all these years of Serena making herself feel dominant simply due to her older age, this newfound control he had over her felt refreshing.

The microwave beeped, and Serena reluctantly pulled the hot bag from the microwave and marched back into the living room, her movements stiff with anger. Without a word, she held out the popcorn, her eyes refusing to meet his.

Kai reached out to grab it, his attention momentarily shifting to the steaming bag. Serena's eyes locked on to the remote sitting on the armrest of the couch. She moved as fast as lightning, her hand darting out to snatch it.

But Kai was faster. He grabbed the remote away just before her fingers could close around it, holding it high above his head as he looked down at her with a disapproving shake of his head. "Too slow, sis; better luck next time."

His eyes gleamed with satisfaction as he watched Serena's face twist in frustration. He leaned in closer, his voice low and taunting. "Let me remind you," he said, tapping the remote with his finger. "I've got full control now. I can press the button again whenever I want." He let the words hang in the air, watching her flinch. "But I won't... as long as you cooperate."

"You're unbelievable," she glared at Kai, who looked far too pleased with himself. "What's wrong with you? Listen, I'll give you the receipt, if that's what you want. Just stop all this, please!"

Kai's grin widened as he reached into his pocket, pulling out two crumpled pieces of paper. He unfolded them slowly, letting her see every crease, every line of text. Her eyes widened in horror as she recognized one of them instantly--the very receipt she had used to control him--and then she saw her own receipt, and she stumbled backwards.

"These?" Kai asked, his voice dripping with mock innocence. "You're too late; I already got them both." He waved the receipts in the air before tucking them back into his pocket.

Serena's face crumbled, and the fight drained from her posture. She just looked at him, eyes wide open.

"You went into my room without permission and went through my stuff?" Serena croaked, her voice filled with disbelief. "I... I don't feel like I could trust you anymore

"Don't need you to," Kai shrugged casually.

"Kai... I'm sorry," Serena stammered, her voice cracking. "I shouldn't have made you do all my chores. I was wrong, and I know that now. Please... put an end to this."

Kai's expression did not change, his eyes narrowing as he watched her try to backpedal. A bitter laugh escaped his lips, and he shook his head slowly. "You're crazy if you think I'm just going to let this go."

"I... I have some money. It's not much but--"

"Money?" Kai cut her off, his voice low and menacing. "You think a little cash will convince me to forgive and forget everything you put me through? For weeks, you used me like a tool to do everything for you! And now that I've got the upper hand, you expect me to just... let go of it?"

Serena opened her mouth, but no words came out. She looked away, her face burning with shame.

Kai scoffed. "No way, sis. You've had your fun, and now it's my turn."

Serena's nostrils flared before she turned on her heel and stormed towards her room, her footsteps heavy with defeat.

Just before she reached her room, Kai fired up her device again. This time, he also added 3 more presses. The device was now powered up to level 4.

Serena yelped sharply as her knees buckled, sending her to the ground again despite the attempt she made at gripping the wall for support. Her breaths were shallow.

"Where do you think you're going?" Kai demanded.

She stayed on the ground, unable to stand up as her toy's piercing vibrations echoed through her body. She slowly turned to face him, her eyes filled with defiance. "To my room. Where else?"

Kai leaned back, crossing his arms with a smug grin. "Did I give you permission? I don't want you out of my sight." He gestured toward the kitchen. "Besides, you can make yourself useful. Go pour me a glass of orange soda."

As the intense vibrations continued acting on her clit, her eyes widened as she gripped the ground with her hands. The tingling sensation was definitely making herself wet. She let out a loud involuntary moan and shuddered.

"Woah, that's kinda weird," Kai's eyes widened in mock offense as he leaned back on the couch. "You're my sister. I don't need to hear your moan."

Her eyes blazed with fury as she snapped back, "You fucking asshole! You're the one causing it... you... you... disgusting pervert!"

"Call me whatever you want," Kai shrugged, completely unfazed. "I'm not a sicko like that, believe me. I'm just trying to get some orange soda."

Serena felt herself getting wetter and wetter around her device and sensed that an orgasm would be coming soon. She fought back another moan, her hips shaking uncontrollably as she used every possible muscle to try and control her body. On the bright side, if she did manage to reach orgasm, she would relax, and her vibrator would temporarily no longer be such a burden to her. But the toy was under her brother's full control, and she didn't want to give him the satisfaction.

Suddenly, the toy powered down, and Serena breathed a long sigh of relief, although she felt a little disappointed. She was so close to the edge--mere seconds from orgasm--but she didn't quite get there.

"I'm still waiting on my orange soda." Kai reminded her. "You've got 30 seconds to get me a glass."

Serena was still on her knees, recovering her breath. "I almost just came, you bitch!" she yelled out, her voice cracking.

"Ewww," Kai scrunched up his face in disgust. "TMI, sis, TMI."

Serena's hands balled into fists, her panting body practically shaking with anger. "Give me time to at least stand up first!"

Kai's gaze was unrelenting. "This is all payback," he reminded her, his fingers casually tapping his pocket where the remote was safely tucked away. "You tortured me for weeks, and I endured it all. Now the tables have turned, and not even 10 minutes in, and you're already losing it."

Her eyes widened in disbelief. "This is totally different! I just made you do my chores. You... you hijacked my vibrator! What kind of brother does that to his own sister? You're sick, you know that?"

Kai merely arched an eyebrow. "Thirty seconds, Serena. Clock's ticking."

Serena's face filled with rage, but she knew he wasn't bluffing. Her teeth ground together as she made her way towards the kitchen. She walked slowly, not only because she was dazed but also because she could feel the wetness of her damp underwear, beginning to spread subtly through her leggings.

"I can't believe you're my brother," Serena muttered under her breath, not caring if Kai had heard her.

She grabbed a glass and filled it with orange soda, the liquid fizzing angrily, mirroring her mood.

She stomped back into the living room and shoved the glass toward him, her eyes cold. Kai accepted it with a satisfied nod, his fingers brushing hers just long enough to see her flinch.

"That wasn't so hard, was it?" He teased, taking a long sip.

"Just so you know," Serena stood before him. "This is the worst day of my life."

"Oh, I'm glad to hear that," Kai smiled in satisfaction. He didn't even look at her, his eyes still on the screen. "By the way, my laundry is piling up. You can take care of that for me."

Serena opened her mouth to protest but bit her tongue. A brilliant idea suddenly came to her. She nodded to Kai and headed towards his room without further question.

Stepping foot into his room, she was out of his sight at last. This was her chance.

Serena pulled her leggings down, then her thong too, feeling the soaked fabric peel off her private area. She was much more wet than she had thought. She reached down to remove her vibrator, which was her only option if she were to make Kai lose his leverage.

Then, a surprising jolt ran through her body as her toy suddenly came back to life. Serena muffled a cry of shock as she dropped to her knees, her leggings and thong still sagged down below her knees. Fighting the sensation, she moved her hand frantically towards her vibrator once more. She was not going to give up; she had to remove it--it was the only way to save herself.

"Kai, knock it off!" Serena screamed, the new panicking thought of her brother seeing her like this adding to her already stressful situation. "And don't come in! I'm... I'm--"

Her fingertips had barely made contact with her vibrator when she felt an increase in intensity. Level by level, the strength of the vibrations climbed. She gasped, her eyes widened in alarm and horror as she realized she was powerless to stop it.

"Stop!" Serena's wail turned into a moan as she felt the speeding sensation. "Stop it!"

Serena leaned forward all the way, planting the palms of her hands firmly on the ground and laying her head down on the cold hardwood floor, tilting it to the side. The waves of vibration felt amazing, and she couldn't help but moan with pleasure. Trembling heavily, her breathing kept quickening, and she could feel herself approaching climax once more. She moaned deeply, not even trying to hide the fact that she was loving the sensation, despite everything else being so messed up.

"I had a feeling you'd try something like this."

Serena's blood turned to ice when she heard Kai's voice behind her. She was currently stuck in an almost perfect doggystyle position, her ass high up in the air and fully exposed. It was quite possibly the most vulnerable and humiliating position for her brother to see her in.

"You're calling me a pervert?" Kai chuckled, not wanting to look at his sister. "You're the one currently mooning me. I can see everything, you slut."

"That wasn't my fault!" Serena screamed; the vibrations were becoming almost too much for her. She then felt the intensity of her vibrator disappear all at once, then flicker on to the lowest setting.

This temporary relief allowed Serena to muster up enough strength to turn herself around to face Kai. He was standing by the door, his arms crossed and his eyes blazing with amusement.

"You know, I have to say that the range of this remote is quite impressive," Kai laughed. "I was still in the living room when I turned your little friend on."

Serena barely heard him as she steadied her breathing. "You sadistic fuck!"

Kai ignored her, taking a slow step forward. "I told you to do my laundry, and did you listen? No, you tried to get rid of my authority over you. You had no chance in hell, Serena. Your little brother isn't as dumb as you thought."

He stood over Serena as he looked down on her in her pathetic state, body trembling and shoulders hunched in total defeat. It was quiet, with the exception of the small humming sound coming from her idling vibrator.

"Look at you," Kai scoffed, his voice full of contempt. "Pathetic! What happened to all your confidence? All your attitude?"

Serena's lips trembled, but she kept her head down, refusing to look at him. She casually moved her hands towards her thong and leggings in an attempt to pull them back up, but Kai reached down and swatted her hands away.

"You think covering yourself up will fix things?" Kai's eyes narrowed with disgust.

"Yes!" Serena's voice cracked harshly. "Unless you want to keep looking at your sister's naked ass like a perverted creep!"

Kai simply pointed behind Serena, his finger steady and accusing. "Look at that," he sneered. "Look at the nasty little snail trail you left behind."

Serena's face went pale, her body freezing as shame flooded through her. She turned slowly, her eyes widening as she saw the glistening trail on the floor, a humiliating testament to her wet, dripping pussy. Her hands flew to her mouth, a choked sob escaping her lips.

Kai's laughter was cold. "You're a mess, Serena. A bratty, dirty, pitiful mess."

Serena's lips trembled as she lowered her head. Normally, she would've snapped back and fired off a sharp remark. But now... she didn't have the energy. The fight in her was gone, shattered along with her pride and dignity.

"You're going to clean that up, every last drop. And don't even think about leaving a single stain. You hear me?"

Serena had no choice but to nod.

"But... since you've already made such a big mess, I can help you finish up. Consider it my gift to you."

"What?" Serena cried out in dismay as her vibrator revved up again. The faster and faster vibrating waves made her entire body tremble and her hips shake violently. Kai then turned the device off, and the disappointment she felt was immense.

Serena now understood just how grave the situation she was in was. Kai wasn't using the control he had on her vibrator to manipulate her to do little tasks anymore--he was now using it to torture her. She had been edged so close to completion twice now, and she knew that her pussy was dripping like a faucet, evidenced by her own fluid on the floor. Serena prayed that this third time would be the charm, and she could finally be at ease.

Between the humiliation and sexual pleasure she felt, tears welled up in her eyes as she didn't know how long she could go on like this. She hated that her brother possessed full power over her toy, but a little part of her felt excitement at the prospect of someone else controlling it. It was unexpected, kind of like closing your eyes on a roller coaster and knowing the adrenaline would kick in, just not when. She just wished that person was a boyfriend, not her own brother.

Serena braced herself as her vibrator increased in power once more. She was well aware the impending eruption from her pussy was going to be violent. She suddenly felt the warm sensation of her juices starting to trickle down her legs. She was exposed, vulnerable, and mere seconds away from coming super hard.

Kai's eyes gleamed with wicked curiosity as he watched Serena struggle on the floor. "Tell me, Serena," he drawled, his voice full of condescension. "Are you able to have multiple orgasms in one session, or are you the one-and-done type?"

Serena's head snapped up, her eyes wide with shock. She hesitated, her mouth opening as she struggled to find the words. "How could you ask me that? You're my brother!" Her voice cracked again from duress. It was none of his damn business! Shame and humiliation twisted in her stomach like a tornado of butterflies, burning her from the inside out.

Kai leaned in so close that Serena could feel his hot breath hitting her bright red face. His eyes bore into hers, leaving her nowhere to hide. His voice was low and taunting. "Come on, sis. You can tell me."

The orgasm built up inside her again as the vibrator continued to enchant her with its magic. Her chest tightened, her vision blurring as the walls seemed to close in around her. It was happening again. Her body trembled, her palms holding on to the floor for dear life. She couldn't take it anymore. The humiliation, the desperation, the unwanted pleasure--it was all too much. Kai had her cornered, and she was completely at his mercy.

"One-and-done," Serena's lips quivered as the words slipped out, barely above a whisper. "After one orgasm, I'm done, and I need quite a lot of time to recover."

Serena looked away, her face burning with shame, tears welling in her eyes.

"I see," Kai curled an eyebrow. "And what level do you usually have your toy set to when that happens?"

"Level 5," Serena instantly confessed, afraid that her brother would do something else evil to her. She couldn't believe that she was spilling all of this out to her brother. "I've never gone past level 5. I don't last that long; I reach orgasm really easily, and when I do come, it's explosive."

"Again, TMI, sis," Kai shook his head in disgust. "No need to paint a whole picture for me."

Serena's body shook uncontrollably as she fought back her inevitable orgasm. Her shoulders quivered with every panting breath. Her nails scratched into the hard surface of the hardwood floor, but the pressure was nothing compared to the burning humiliation that tore through her. Every shred of dignity she had left was being stripped away, leaving her raw and vulnerable.

The vibrator shut off once again, and the sudden absence of the sensual vibrations was sheer torture for her. She couldn't stand it anymore.

"Stop torturing me, Kai," Serena gritted her teeth, her breathing shallow and irregular, a direct result of the frustration she felt from being teased so much. "Please just allow me to finish, and then I'll clean this whole mess up. Please!"

Kai simply stared at her, a satisfying smile on his smug face. "Seeing you beg feels so satisfying," he taunted. Vengeance was underrated; it felt so good. It was so satisfying to reverse the blackmail that tortured him for weeks and transfer it to Serena.

Serena flinched, her heart skipping a beat. Kai counted the presses on the remote as he powered on her toy once more. He stopped once he reached level 5.

Serena was forced to brace down into a doggie position once again as the sensation overcame her body. "Oh, oh, OH!" Her moans grew in volume and frequency as her toy vigorously ravished her already soaked vagina. She let out a huge moan as her body once again was ready for a climactic release. But it never came. Kai had suddenly powered off again, putting a pause to the strong vibrations just as she was so close to coming.

"God fucking damn it, Kai! You're such an asshole!" Serena cried out in despair, tears falling down her face. "Stop edging me so much! Please! I can't take it anymore!"

Her shoulders shook as she tried to stifle her cries, her whole body trembling from frustration. Serena wanted to disappear, to sink into the floor and escape his piercing gaze. But she couldn't. She was trapped, soaking wet, and horrifyingly fully turned on and hoping to come. All in front of her own brother!

Kai's voice dropped, icy and mocking. "You really want to finish? I thought edging felt really good."

"It does," Serena nodded weakly, her face burning with shame. "But after a while, it becomes torture! I'm ready."

Serena then began to uncontrollably laugh, her emotions completely dissociating from her. Kai even stepped back, mortified. Why the hell was she laughing? Was it because she was in such an embarrassing state, her pussy dripping all over her brother's bedroom floor? Was it because she was secretly enjoying this, allowing someone else to be behind the wheel of her remote? It didn't matter. She was already so close to sweet, sweet relief.

"Make me come." Serena didn't dare look up at Kai as she spoke those words. She was really, really turned on right now and wanted him to take her to the finish line. She started to sound desperate. "I'm so incredibly horny and wet right now; you're killing me. I need to come! Hurry, please!"

Kai's eyes widened as Serena's words echoed in his mind. He couldn't believe what he'd just heard. The same sister who had controlled him for weeks was now begging him to allow her to finish. He had won. This revenge, this sweet, cold vengeance, felt like bliss. He savored the victory, knowing Serena would remember this moment forever.

Even if she somehow got dirt on him again in the future, she would think twice before daring to blackmail him. This experience would haunt her, torturing her memory for years--maybe even for the rest of her life. Kai had insurance now, a safeguard that ensured his permanent reign of power over her. To say it felt incredible was an understatement.

"As you wish, sis," Kai sighed, activating the device once more, leveling out at level 5.

Serena released a long moan as she felt the excitement once more. Her eyes closed and lips parted; she sighed softly as she tried to steady her trembling body. When she blinked her eyes open, she was staring hard at the ground, deliberately avoiding eye contact with her brother.

But Kai wasn't done with her. He had already gone too far, but he needed to go all the way. His fingers suddenly grabbed hold of Serena's chin, tilting her face upward. Her eyes were wide, shimmering with fear and humiliation. It made him feel so powerful. Her cheeks were bright red as his smug grin widened, taking full pleasure in her total vulnerability.

"I want to see what this baby can do," Kai stated, holding up the remote for her to see. "You better buckle up."

Serena's lips trembled, her instincts screaming to defy him, to shout back and stop. But she found herself hesitating. Did she want him to? She never tried anything past level 5, and the idea of higher levels made her tingle with excitement.

Serena heard the audible click on the remote and felt her vibrator's power creep past level 5, going beyond her comfort zone.

"Level 6," Kai announced the new level.

Serena was in uncharted territory now. "Oh my God! OHHH..."

She couldn't help but begin pumping her hips and letting out quick, high-pitched whimpers.

"Level 7," Kai announced, smiling as he watched his sister's helpless, trembling body.

"Oh YES!" Serena screamed high as her whole body rocketed towards the orgasm that she had longed for. She couldn't help but squirt a little onto the floor in pleasure.

Serena suddenly gripped Kai's shirt collar, her knuckles turning white. She pulled him closer, her perfume wafting over his senses. Her voice was shaky but firm.

"Keep going," Serena demanded, emitting another loud squeal as her vibrator buzzed intensely like a hive of angry bees. "Crank it up all the way! I want more! MORE!"

For the first time, Kai felt a chill run down his spine as he stared into her eyes. They were familiar from all the porn videos he watched--but they were not the same eyes he ever wanted to see in his own sister. He flinched in horror as he recognized it: the fuck-me eyes.

Kai had thought those eyes were hot as hell, but on his own sister? For the first time during this whole revenge scheme, he regretted what he had done. But it was too late. His sister was fully aroused now, probably so close to reaching her limits. He couldn't bear to torture her more.

Obliging, Kai added one more click. "Level 8."

Immediately, Serena let go of his shirt, her hand falling back to the floor in order to support herself as she adjusted to this new fierce sensation. Before she had gotten used to it, her raging horniness convinced her that she wanted more. No. She needed more. She was speeding towards the point of no return, and she wanted to get it all out of her system.

"Keep going!" Serena begged. "I want--"

Serena was interrupted by her own long, loud squeal that pierced Kai's ears. She slapped the ground repeatedly, and her hips bucked wildly as she loudly let out a moan so loud that she wouldn't be surprised if their next-door neighbors heard. Her already sopping wet pussy contracted over and over again. Squirting and ejaculating at the same time, the hot juices burst out from her pussy outwards and sprayed all over the floor. Kai jumped back in surprise. Her fluid continued to drip out, and she felt like life was slowly being drained out of her, but in a good, sensual way. With one last squeal of delight and a soft whimper, Serena's soft body relaxed and collapsed onto the floor.

"God, that felt so gooood!" Serena moaned.

Kai's face went pale as he stared down at his sister. "Did... did you actually finish?"

"I already told you, I come easily," Serena laughed as she steadied her breathing. A trickle of sweat dripped from her forehead. "Why? Did you think I would fake it?"

It was obvious that she hadn't. Serena's pussy was drenched; the remainder of her warm juices flowed down her legs, contributing to the pool of it already splattered on the ground. A little trickled onto her thong and leggings.

"Level 8, new high score," Kai chuckled nervously, trying to lighten the mood.

As Serena's body gradually returned to its normal state, the reality of her situation hit her. The fog of dangerous horniness in her faded away as the sun of clarity appeared in her mind. She stared back at the sticky liquid pooling across the hardwood floor in messy pools, with additional splatters here and there. She then looked up at Kai, expecting him to continue to belittle and make fun of her. But instead, he just stood there, his eyes fixed on the mess.

For a moment, it all felt like a dream. No, make that a nightmare. Everything that happened was so bizarre, and she couldn't bring herself to process what had just occurred. Her brother had just brought her to orgasm--using her own vibrator! It didn't help that in her blind heat, she had begged him to increase the vibrations further, like some slutty whore.

Kai took one last look at the mess she created, and moving quickly, he grabbed a towel from his drawer and tossed it in front of her.

He didn't meet her eyes as he turned and walked out of the room. He returned moments later, holding three items: the remote, her receipt, and a button cell battery. He gently set them on the floor beside the towel. Serena was relieved. She knew that this was finally the end of his revenge.

"Just clean your mess up," Kai muttered. "Then get out of my room."

Serena sat frozen on the floor, the towel crumpled beside her. Now they both shared a deep, dark memory, one that could never be spoken aloud. Her hands trembled as she plucked out her vibrator from within her and started to wipe the mess off herself.

"You better toss that towel when you're done," Kai shuddered in disgust.

As Serena pulled her thong and leggings back up, her mind continued racing. What if Kai mentioned this to his friends? She quickly ruled out that possibility. He would become a social outcast if he broadcasted the fact that he gave his own sister an orgasm, even if it was through a vibrator and not... well that.

When Serena finished cleaning up the best she could, she took one last look to make sure there was no trace of her remnants left behind. Satisfied, she slipped out and headed toward the bathroom, the towel in one hand and her toy and battery in the other.

On her way there, she passed the kitchen, where Kai was standing by the counter. He had his back turned to her, and his shoulders were stiff and tense.

"Is it done?" Kai asked, his voice lacking any emotion. It was obvious he didn't want to look at her, and she couldn't blame him. She felt the same way.

"Almost," Serena replied tersely.

Once she was in the bathroom, she shut the door and leaned against it, letting out a shaky breath. Her heart was pounding. She washed her toy in her sink thoroughly, knowing full well she could never look at it the same way again. Then she soaked the towel and wringed it dry so she could go over his room's floor one last time.

Serena dropped her leggings and thong, wincing as she looked at how messy both had gotten. Sinking onto the toilet seat, head in her hands, she couldn't stop replaying the memory over and over again as she peed.

As her deep shame started to fade, a new feeling came over her: a sharp sensation of resentment. She was mad. Mad at him for blackmailing her, mad at him for controlling her, mad at him for pushing her to orgasm.

Serena had started the whole blackmail of Kai, sure, but what just happened to her felt like a violation of herself that she didn't deserve. Her eyes narrowed with a spark of defiance. She wasn't going to let him think this was over. Not like this.

As she flushed the toilet and wiped herself, the guilt and shame she felt were gone, now replaced with determination. She washed her hands, staring at her bloodshot eyes in the mirror's reflection.

Serena dropped off the toy in her room to dry, then shuddered as she removed her soaked thong and her fluid-stained leggings before chucking them into her laundry basket. She grabbed some body wipes from her desk and wiped herself clean before changing into a fresh thong and dark blue jeans.

Then she made her way to Kai's room. After one last thorough wipe of his floor, she stood back up, pocketing her own purchase receipt in her jeans. Her eyes drifted over to his laundry basket that had his dirty clothes overflowing out the top. If it wasn't for Kai's order to do his stupid laundry, she wouldn't have come into the room in the first place. She made her way over and kicked the basket over in frustration. Clothing tumbled out in a messy heap, spilling all over. She was about to curse under her breath when something shiny caught her eye.

Amidst the pile of shirts and shorts, a small silver object revealed itself. Serena's heart skipped a beat. She knelt down and picked it up, her fingers curling around the cold metal.

Kai's room key.

She turned it over in her hand, her pulse quickening as realization sank in. It must've fallen out of his shorts pocket. He probably didn't even remember where he'd last put it.

This was it. Her ticket to revenge. She came up with an idea almost instantly.

If everything went according to plan, she could make a copy and return the key before he even noticed it was gone. But she would have to be fast and be able to sneak his key back into his room before he started looking for it.

After that, she would have access to his room whenever she wanted. The possibilities were endless. And the best part? Kai would never see it coming.

Her grip tightened around the key as she tucked it in the back pocket of her jeans. She stood the basket back up and picked up the spilled clothes. Glancing at the room one last time, making sure everything looked just as she found it, she walked out. She put on a fake smile as she stepped out of Kai's room and walked to the kitchen. Kai was still there, holding a glass of water. He looked up, his shoulders tensing before he awkwardly cleared his throat.

"Uh... thanks for cleaning up," he muttered, his eyes avoiding hers.

Serena smiled as she leaned against the counter. "No problem."

Kai glanced at her, relief softening his features. "So... we're even now, right?"

Serena fought the urge to scoff. Even? In his dreams! But she couldn't let him know that. She needed him to be completely off-guard as she planned her sneak attack. "Yeah, we're even."

Kai let out a sigh, his shoulders visibly relaxing. "Good. I'm... glad." He turned and walked to his room, shutting the door behind him.

He thought he was safe, didn't he? Serena smiled to herself.

It was time to put her plan into action.

She glanced at her reflection in the kitchen window. Her already messy hair was messier, and her body was sweaty after the whole ordeal, but she only had so much time. Lacing up her shoes, she left the house quickly. Her hands gripped the steering wheel as she drove to the local locksmith. She held the key tightly, its cold surface pressing into her palm. She walked up to the counter, presenting the key casually. Then she tossed her receipt into the trash can. Nobody would find her evidence in here.

The locksmith inspected the key, then shrugged. "Ten dollars."

Ten bucks was a lot, considering her tight college budget, but she knew this would be the best ten dollars she'd ever spend. She handed over the money without hesitation, watching as the man made a perfect copy of the key.

Her mind raced with possibilities as she drove home. What could Kai be hiding in his room?

Serena quickly pulled into the driveway. Her heart pounded as she entered the house. Immediately she noticed the bathroom fan humming, which meant Kai was occupied.

She suppressed a giggle of excitement. It was all going to plan. She moved swiftly, keeping her footsteps light and quick as she approached Kai's door. She slipped inside, her eyes scanning the room. Everything looked exactly as she'd left it.

She made her way to the laundry basket and buried the original key beneath a pile of clothes before exiting, making sure to close the door softly behind her.

Serena walked to the living room and turned on the TV, trying to calm her racing heart. She didn't even register what was on the screen; her mind was too busy strategizing her next move.

Moments later, Kai stepped out from the bathroom. He glanced at her, relaxing as he saw her casually lounging on the couch, before heading back towards his room.

Serena's eyes remained glued to the screen, but she wasn't paying attention to the show. Kai thought they were even. He thought he was safe.

Oh, Kai had no idea just how wrong he was.