First Sin - Hot Springs, Pt. 01

My wife, Sarah, and her younger sister, Beth, could be twins. They both have the same long wavy hair, smooth legs, small waist, tight ass, D cup tits and both are stubborn brats. Their relationship has always been strained and a bit weird, and Beth would keep intruding on our dates before we got married. Beth was an insufferable little bratty princess whenever her sister was around, but would chill out when it was just her alone and could be a bit fun to hang out with. Still a bit bitchy though.

One year Sarah, my then girlfriend, made the mistake of telling her family we were going to this mountain hot spring resort for a long weekend. So guess who showed up the same day as us? Beth did. In-laws were there too, but pretty much just hid in their room the whole weekend. Sarah was pissed and said our romantic getaway was ruined and started going off about her sister and how 'this is just so like her!'.

I was disappointed because Sarah's family was getting to her so bad that she couldn't relax and just enjoy the trip. She started texting her mom from our room and rather than just sit there and be a witness to their drama I told her I'm going to go enjoy the pool and spa. I honestly didn't know if she even heard me but she muttered 'yeah whatever, have fun'. I headed out and went outside.

This place was built on top of a natural hot spring so the pool was always warm, even in winter. There were a bunch of hot tubs scattered around and some mini hot tubs that had privacy tents like a teepee. I swam some laps in the pool and played around a bit, but it was pretty boring being a grown ass man by myself in a pool shared with families and kids. I got out and decided to relax in one of the mini hot tubs before going back to the room.

I got in, closed the tent flap and slid into the hot tub. The water was steamy, it was nearly pitch black and I had a view of the stars theough the little opening at the top. The only thing that would have made it better was if Sarah had chilled the fuck out and was there with me.

Then some asshole opened up my tent flap and let out all the steam that was building up. I couldn't see them right away because the outdoor pool area was lit and there were no lights inside the tent.

"This one's taken," I said.

"Oh, it's you."

"Beth?"

"Yeah. Where's Sarah?"

"I dunno. She was upset and texting your mom. I told her I was coming out here and she stayed behind." Beth just stood there at the entrance for a minute. I couldn't see much of her; she was wearing a big fluffy robe from the resort.

"Are you going to get in or what? You're letting all the steam out."

Beth ducked inside and closed the tent flap behind her. She dipped a toe into the water, then untied her robe. I had been around Beth enough times to know she had to have a nice body, but never before had I seen her in a bikini. She did track in high school and still looked like she exercised regularly. She was lean but any amount of fat went straight to filling out her hips and breasts.

Beth slowly sank into the water and moaned. "Oh, this feels so good. Is Sarah going to come out later?"

I was so thankful the tent was dark enough that Beth couldn't see my eyes staring at her tits floating in the water. "I don't think so. She's really pissed you decided to crash our weekend."

"Whatever. She doesn't own the place."

"I mean, you know what you were doing, right?"

"So," she said. "It's not fair. I can have some fun too."

"What are you even talking about? You know what, forget it. You two have a thing, I don't want to be a part of it. Could you just please give her some space so she'll chill out? For me at least?"

Beth sat there quietly across from me for a long time. The hot tub was small enough we could have high fived without getting up. I felt Beth' foot touch mine under the water, then it moved up my leg. I shifted away a little bit, but there wasn't really anywhere to go other than out of the tub.

"What're you doing?" I whispered. She slid off her bench seat and drifted over to me.

"What do I get?"

"The fuck you mean 'what do you get'?" I moved around the hot tub trying to get some distance from her, but she kept following me. Beth stood up and even in the dark tent I could see the water run down and drip off her huge tits. She pulled her hair back into a ponytail, which made her breasts push forward and nearly smother my face.

"Sarah always gets whatever she wants. I want what she has. I want to be on a romantic weekend, too."

I put my hands on her soft, squishy delicious hips to hold her back. "This is nuts, Beth. We can't do this."

"Then stop me." She leaned in and kissed me. Her lips were full and soft. I felt her tongue lick my bottom lip. I couldn't think straight to take my hands off of her, so instead I held her tighter. She took my hands and put them on her tight little ass all the while kissing down my neck and giving me little nips with her teeth.

"You're not stopping me," she breathed. "Just give me this and I'll leave you alone. Pretend I'm her." I squeezed her ass and massaged my fingers into the cleft between her cheeks and her thighs. Beth moaned in my ear and her hand started rubbing my crotch. I was already getting hard before she touched me but now my dick was throbbing and begging for more.

I tried to put a hand on her chest to push her away but got a handful of boob instead. Beth gasped, then she untied her bikini top and let it drop. Her tits were perfect; large, rounded with stiff little nipples that poked upwards. She leaned forward and forced me to sit back down on the submerged hot tub seat bench. Beth climbed on top of me, straddling me with her strong, lean thighs. Her tits were practically in my face.

"I always guessed you were a boobs kind of guy," she said, giggling. "Are mine better than Sarah's?" She sat up a bit, pressing her tits on both sides of my face. I couldn't do anything except breathe in her scent. I felt a sharp nipple graze my cheek and turned my head slightly to catch it in my mouth. I didn't know what I was doing anymore. In the dark she looked like Sarah and her husky whispers and moans were close enough that it was easy to pretend it WAS Sarah.

Beth gasped again as I sucked and bit on her nipple. Her other hand went behind my head to scratch my scalp and pull me into her sweet smelling chest. "That's it," she cooed. I felt her hand go under the water and untie my drawstrings. She had her fingers wrapped around my hard cock a moment later and started stroking me.

I took my mouth off her succulent tit and tried to sit up, but she kept me pinned down. "We need to stop," I said.

"Make me," she whispered back. She squeezed my dick and and started rubbing my cockhead along her bikini bottom. She was so fucking hot and wanted me so bad it was scrambling my brain. Sarah was never like this: needy and begging for me. It would just be one time and then Beth would back off and I could just focus on Sarah for the rest of the trip.

"Tell me something she would never do," Beth asked, kissing my ear, rubbing my dick along her clothed pussy.

I grunted, lifting her up and out of the water a bit so I could sit up. She stayed rooted on my lap with her hand around my cock and her tits floating in the water just in front of my face. "Blowjob. She hates them."

Beth grinned then ducked underneath the water. I couldn't fucking believe it. I felt her hands push my legs apart and then her tongue lap at the tip of my dick. She slid my foreskin down with her lips, swallowing my glans in one go. I hunched forward, unused to the tight, almost painful feeling of a tight mouth sucking down on me and teeth grazing my shaft.

I grabbed the back of her head, holding her in place, not wanting for her to let me go. I watched the tent flap as Beth sucked me off under the water, paranoid that someone was going to catch us. After about twenty seconds of Beth sliding her hot hollowed out mouth along my cock she tapped on my hand that was holding her down. I let go, and she popped out of the water with a gasp, grinning.

This crazy bitch was going to get us both in deep shit if this took too long. Sarah would eventually go looking for me, or a resort worker would poke their head in the tent to check what all the gasps and moans were about.

Beth took a deep breath and was about to duck under the water again but I stopped her and spun her around to sit on the bench. "Shut up before you get us caught," I hissed.

She giggled. She fucking, GIGGLED. "Make me," she said sweetly.

I had enough of this psycho brat. If she was so desperate I was going to give it to her so hard she'd be limping the next day and leave me and Sarah alone forever.

I grabbed her by that cute, tight little ass and lifted her out of the tub, making her sit on the edge. I pulled her legs apart and yanked her skimpy bikini bottom to the side. I could smell her musky pussy aroma right away. She leaned back and spread her wet labia for me. "Fuck yes, please!" she whined. "Use me like I'm her."

No fat fucking chance of that. Sarah was a prissy prude. Beth was a slut.

I rubbed my palm along the outside of her snatch. Beth moaned and gasped when I slipped a finger in her tight, hot hole. I slid my hand up and down her soaked pussy lips and pushed another finger inside her. Beth squeaked and stopped breathing for a minute before taking slow laborious breaths. I curled my fingers inside her, grinding against the rough patch of her g-spot just behind the pubic bone. Beth began squirming in my grip and thrusting her hips into my palm, her feet kicked, splashing water everywhere.

I kneeled down and licked along her puffy swollen lips. I could taste her juices spilling out of her and wanted more. I pushed a third finger into her overstretched hole and sucked down on her clit. Beth bucked her hips and yelped. Before I could react I felt a warm, acrid tiny splash against my face. Beth began to moan, loudly, and crush my head between her lean muscular thighs. I pulled my fingers out, wiped the slick coating on her bikini panties, and left her gaped open. I clutched her slender throat.

"Be quiet!" I whispered. She nodded but was breathing too hard and fast to say anything. My cock felt like it was about to explode. I pushed her legs off of me and flipped her over onto her belly. Her boobs made a delicious flap as they smacked on the stone floor. She looked back over her shoulder at me, panting for air, her legs shaking as she spread them open for me. I slipped my hands under her chest, cupping her heavy tits in my hands as I laid down on top of her. My cockhead brushed the opening of her gaped leaking slit, twitching with anticipation to stretch her open even more. Beth rubbed her face into my neck, desperately kissing and licking me for attention.

"Yes," she begged, "make me yours." Beth arched her back, trying to impale herself onto my cock, and grunting with frustration when I moved back.

I growled in her ear, "Are you going to be good and leave me and your sister alone?"

Beth spat, "Make me!"

I squeezed her tits, hard, and thrust my dick into her cunt down to the hilt in one push. Her tight pussy gripped onto my shaft and sucked me in, making a lewd squelch as I pushed all of her leaking pussy juice back inside her. Beth' s legs spasmed and she began to scream in pain and euphoria, but I covered her mouth. I pressed my weight down onto her, savoring the sensation of her sweet warm hug of inner muscles as they clenched and pulled me deeper inside of her. Beth slapped her hands on the ground and started trying to push herself back into me but she was too weak by now.

She was mine.

I slid my dick nearly all the way out of her, leaving just my cockhead in the grip of her ring of muscle around her entrance, then thrust back in, and again and again. She bucked and pushed back as much as she could, moaning into my hand that smothered her cries. She looked up at me with teary puppy eyes that begged for more.

I stood up, pulling Beth up with me, and fucked her from behind. Her back was arched out in a seductive curve and her big tits bounced with each thrust, clapping together with a wet plap. I grabbed her ponytail and yanked her head down, forcing her to look straight up at the stary skies. I bit down on her neck just above the shoulder and she let out a sharp grunt.

"Wait, I'm... I'm..." I didn't give a shit what she had to say. I fucked her harder, her ass slapping agaisnt my thighs and making the water spalsh over the sides. "I'm not on the pill!".

Fuck. FUCK! More than anything all I wanted was to fill that stupid bratty bitch up. I punched my cock hard into her quivering snatch twice more. I was about to blow my load all over in her warm, soft velvety grip. Beth did nothing to stop me; just gasped and held on to my arms slamming her up and down.

"Fuck I'm cumming!" I pulled my dick out of her heavenly, dripping hole and sprayed cum all over the inside of her thighs. My cock was coated in her sweet fluid. Beth yelped and nearly collapsed. I held onto her and raked my teeth along her sweaty neck, up to her jaw. Beth was shaking, barely able to stand.

"Please," she said, voice hoarse and shaky, "kiss me?" She nuzzled my head and tocuhed my cheek with her hand. It was the least I could do for her. Her mouth tasted like candy with a musky undertone. Beth leaned back against me, holding my head so I couldn't get away. I grabbed a tit and pinched her nipple between my fingers, gleeful that I could make her body quiver so easily.

After my dick was done painting her inner thigh, we collapsed back down into the hot spring. The scent of sweat and sex permeated the tight space. Beth sat on my lap, eyes closed, catching her breath. I looked around for my swimtrunks. We were lucky no one came into the tent while we were fucking, then again, maybe they did hear us.

I pushed Beth off my lap, slipped my trunks back on and stepped out of the hot tub. I'd be lucky if Sarah wasn't wandering around right outside looking for me.

"Where are you going?" whined Beth.

"Back to my room. This didn't happen, right? You got what you wanted and now you'll back off and stop being such a brat?" Beth just sat there in the hot spring. I shook my head and flung the tent flap open.

Sarah was curled up on the bed watching a sappy romcom when I got back. She didn't even look at me when I came in. "How was the pool?" she asked.

I told her it was fine, just a bit crowded.

***

The next morning we ate breakfast in the resort dining room. Sarah and her mom must have made up, because they sat with us and had a mostly polite conversation. Beth was absent. My stomach dropped at the thought of how hard we fucked and that I must have left some bruises on her.

Beth walked in just as we started to leave. She moved slowly, almost like it was deliberate, and wore a high collar tight fitted sweater. Sarah glanced at her and strutted off without saying a word. Their parents said their hellos and chit chatted briefly before going off on their own too, leaving me alone with Beth in the middle of the breakfast rush.

"About last night," I said, "are we good?"

Beth smiled and nodded. "We both got what we wanted." I glared at her, and she just giggled.

"You're going to give me and Sarah some space so we can enjoy the rest of this trip."

Beth took a step and leaned in just close enough so I could smell her perfume and her breasts brushed my arm.

She whispered, "Make me."