Sibling Swap

Lindsay lifted herself up slowly, and then back down. Her pussy felt even tighter now. Like her orgasm had stiffened her up. She rocked back and forth. Faster. I could see the skin of her snatch holding on to my cock as she went. Up down. Up down.

It was incredible and all I could do was lay back while the little blonde rode my dick. Oh my God it was more amazing than I'd ever imagined it. I heard a gasp and looked over. Rachel was on the floor, rubbing herself on the carpet. Her face practically glowing.

I patted the mattress. "Come here," I said. Rachel climbed up onto the bed. I wiggled my fingers at her, to say that I'd help her out. But she misunderstood. My sister straddled me with her muscular thighs. Lowered her pussy onto my head. Both best friends now faced each other. What could I do? I leaned up and licked at my little sister's hungry twat.

I heard her gasp. "Ssssoooo good," she said.

"Oh yes," Lindsay said. She was rutting really hard now. The bed squeaked and crashed. If anyone was in the house, having the door closed wasn't going to help. But no one interrupted us. Rachel rode my face while Lindsay slammed herself on my dick.

"Oh fuck," Lindsay said, apparently fucking made her like to talk. "That big dick. It feels so good. I think I'm going to. Fuck."

"His tongue. So good," Rachel said.

"You going to cum?" Lindsay asked.

"Yeah. Yes."

"Me too," Lindsay said, "Oh FUCK. I've never cum just from a cock before. Never cum twice in one... Fuck you're fucking brother's fucking breaking me."

"Me too," Rachel said.

I lay under both of them, subject to their whims. Lindsay's little pussy had me getting close, I could feel it. Yet I hadn't burst yet and I was so proud of myself. Honestly. I didn't want to be like Nick, just shooting off. Hearing that both the girls were about to cum made me feel better than anything else they'd said. Though the stuff about my big dick didn't hurt, either.

Rachel stiffened. She ground her pussy down onto my mouth. Her legs clamped around my head. I heard her gasp. Then she threw her head back and let out a long thin squeal.

Lindsay, as if directly wired to my sister's pussy, suddenly stiffened. "Oh. OH FUCK I can't believe I'm going to... FUCK!"

Lindsay's orgasm overtook her. Her pussy went from tight to impossible. It squeezed down on my cock and suddenly I knew I was about to cum. I started to move back, but both girls held me down tight. I tried to say something, but my voice was swallowed by my sister's bottom. All that struggling made it worse. And suddenly my cock BURST.

A stream of my sperm exploded right into Lindsay's unprotected pussy. Swallowed whole by the little blonde's incredible, fertile womb. The pleasure overwhelmed me.

"Oh FUCK, Rachel it's..." Lindsay cried. Rachel shot forward and wrapped her arms around her best friend. Not understanding what Lindsay was saying. Holding her there, shaking, as blast after blast of her brother's semen splashed into her best friend's bare snath. Inseminated her right there in her parent's bedroom.

Lindsay cried out. Her orgasm peaking even higher than before. I could feel her cunt squeezing me for more. Milking me. Oh God it was incredible. My orgasm rippled out of my cock, up my arms and back.

Rachel's orgasm finally ended, and she slid to the side. The last ebbs of my pleasure shot through and I finally saw Lindsay's face as she tremored with each ejaculation. She looked down at where our groins met. Wracked with pleasure. Swallowed by fear.

Lindsay carefully lifted herself up. A thin string of my cum still connected my cock with her pussy.

"Oh fuck," Rachel said. "Did he?"

"Oh my God," Lindsay said. A thick glob of my semen dripped out of her pussy and landed on my stomach. "He. I mean. It's so much."

"Lindsay I'm sorry, I tried to stop," I said, "Rachel was on top of me and I tried to get away but..."

"Oh fuck," Lindsay said. Another huge glob of sperm fell out of her pussy. Another little orgasm ripped through her body. "Oh fuck oh fuck oh fuck." She might not have wanted my seed inside her, but her womb was focused on the exact opposite - gathering as much sperm as it could. Like stuffing itself full.

The little blonde leapt up and ran to the nearby bathroom. I heard the sink squeak on and a rush of water.

"Oh, Andrew, you didn't," Rachel said. She looked at me angrily.

"I tried to stop, I swear," I said. "It felt so good and when it happened... Why didn't you help?"

"I didn't... I couldn't," Rachel looked at me, green eyes wide, "I mean, I didn't realize you were... Cumming." She looked down at my dick. It jerked at her, happily. Covered in her friend's juices and my cum. A last little bit dribbled out onto my thigh.

*

Rachel and I sat in the bedroom. We didn't say a word. Just listened to Lindsay as she washed herself. I kept waiting for Nick to bust in. I honestly would have been relieved if he had opened the door, seen what had happened, and beaten the crap out of me. I'd have felt rightfully punished. He never did. Where did that boy go?

Finally, after what seemed like a really long time, Lindsay came out of the bathroom. Her eyes were red like she'd been crying. Her whole body was pink. Over-scrubbed. She flopped down on the edge of the bed. Stared at the floor.

"Fuck, Lindsay, I'm so sorry," I said, "I really am."

"I'm probably not pregnant," she said, "I mean, I got most of it out. God there was a lot. But, I mean, I think I'm OK. It'll be OK."

Rachel went over and hugged her friend. Lindsay pushed her away. Looked at my brunette sister, oddly. Like she was putting something together.

"Andy you tried to warn me," she said, "You were about to cum."

"I did," I said, "I'm so so sorry. Whatever it takes, I'll take care of it. You know that."

"But I couldn't hear you because Rachel was over your head," Lindsay said, "And when I tried to tell you that he was cumming in me... Rach, what happened?"

"I didn't understand," Rachel said, "I thought you were cumming so hard that you needed me to... I didn't know. Oh God, Lindsay I'm so sorry. What can I do? How can I make this right?"

Lindsay suddenly stood up. A smile snuck across her face. "I think you should have to do what I just did."

"You want me to... To fuck Andrew?"

"And let him cum in you," Lindsay said.

"But Lindsay," Rachel said, "I'm not on the pill. We don't have any condoms. If he cums inside my pussy he'll get me... Pregnant."

"It's only fair, after all," Lindsay said. Rachel stared back at her friend, the horror creeping up her face.

"I won't do it," I said.

"Yes, you will," Lindsay said, "You want your sister so bad and you know it. You really going to tell me you're going to give up your one chance to fuck her?"

"Andrew, I love you," Rachel said, "I promise. Another time. We'll use condoms or you can pull out I promise. Just not now." But it was already too late. I could feel it in my heart. There wasn't going to be another chance. Something would always get in the way. The moment was now, or it was never. Lindsay was right.

The little blonde walked over to Rachel and pushed her back. "Tell him," Lindsay said, "Tell your brother you want him."

"No," Rachel said, "Not like this."

"Yes, like this," Lindsay said, "You made me fuck your brother. You shoved his cock inside me. You knew I wasn't safe. And when he came, you made sure he couldn't stop. You made him knock me up. It's not fair, Rachel. If I have to have your brother's baby, you have let him knock you up too."

It was, clearly, not a good argument. But it hardly mattered. I'd seen Lindsay's force of personality before. I'd watched her command us to do all kinds of stuff and, obediently, we'd let her. This was just one more down the string. Impossibly, Rachel lay back on the bed. Spread her legs.

"Tell him," Lindsay said.

Rachel looked at me, eyes wide with fear. "Please," she said.

I climbed up on the bed, my cock somehow even harder than before. I looked down at my sister. Her massive chest heaving. That hairy pussy open wide. I saw a bit of Rachel's lubrication leak out. Oh fuck. Her eyes widened with fear as she looked at my spear. Aimed right at her.

Lindsay jumped up on the bed and climbed behind my sister. Gently wrapped her arms around Rachel's upper chest. Holding her there. She stroked my sister's hair and cooed. "Hang on baby, here it comes."

Like on autopilot, I climbed between my sister's legs. Aimed my cock at her cunt.

"That's it Andy. There's a good boy," Lindsay said, "Stick it in your sister."

I lined myself up and slid forward. Holy FUCK my sister was tight. I could barely get the head in before her pussy clamped down.

"Oh!" Rachel cried. She shook her head, "It's too big. Lindsay please it's... Please."

"It's fine," Lindsay said, "Andy's cock was made for his little sister's pussy. You'll see."

I pulled back and then slid a little further in. Rachel shivered. Her eyes got big and she looked like she was about to cry. I rocked in and out. Her pussy gripped on to me. Rachel started panting heavily.

I drew back.

"Give it to her Andy," Lindsay said.

I drove my dick forward and filled my sister completely. She screamed, "Oh God!"

My balls slapped against her butt. I fell forward and held my sister close. Felt her huge tits press against my chest. Lindsay stroked our heads both. "There you go. That wasn't so bad was it?"

Rachel was sobbing. I pushed myself up and looked into her eyes. I kissed her on the lips and, miraculously, she pressed her tongue into my mouth. I reached down and squeezed her gigantic tits. Holy fuck they were fantastic. Even better now with both of us intimately connected. I took my time with them. Hefting and squeezing. Teasing the nipples. I leaned over and sucked at each one. It felt more like worship.

"Stop wasting time and fuck your sister," Lindsay snapped. She really didn't like it when people appreciated Rachel's chest.

I drew my dick back a bit and then slammed into my sister. The need to fuck took hold of me. To drive straight into my baby sis until I reached my absolute peak. Lindsay cradled Rachel's head. My sister's eyes kept getting wider and wider with something like amazement. Then she suddenly stiffened. Threw her head back.

"Oh fuck my brother is making me... CUM!" Rachel shook and squealed. She started crying all over again. Buckets of tears ran down her face and I don't think even she knew if it was pleasure or misery.

I kept fucking her. Her tight pussy felt so good. Lindsay had been amazing but this was so much more. Tighter and wetter and I couldn't escape the fact that it was my sister. My sibling. My love. We moved together like we'd been working at this for eons. Grunting and groaning like animals. Lindsay egging us on.

"That's it. Fuck your sister. Give it to her good."

I felt my orgasm approaching. Rachel's breath hitched again.

"Getting close," I said.

"Fill her up," Lindsay said, smiling wickedly, "Put your baby in your baby sis."

"Andrew," Rachel said, "Please."

I didn't stop to wonder. I didn't pause and think about what I was about to do. I reared back.

With Lindsay it had been an explosion. Cumming in my sister was like an atom bomb. Unstoppable uncontrollable destructive ripping apart everything in its path.

"Ohfuck, ohhhhhhhhh YES!"

A geyser of sperm - not a burst but like a river - shot out of me and into my sister's fertile pussy. She screamed and shook.

"Oh fuck. Oh. Oh. OH! He's cumming in me oh fuck. My brother's filling me up!"

The ecstasy overwhelmed me like drowning in the ocean. Tossing, turning, gasping for air all of it swallowing me up as I bellowed out every blast of fertility into my little sister's unprotected pussy.

Lindsay held onto Rachel tight while her best friend bucked against the bed. "Shhhhh," the blonde girl said, "It's OK. I've got you. It's alright. Take it. Like a good sister should."

Another explosion. Then another. I filled my sister with everything I had and then gave her some more besides. Nineteen years-worth of frustrated fertility - like I'd never cum before in my life and all that time was simply saving up for this moment.

I looked down and saw that Rachel was sobbing, her body trembling with orgasm after orgasm. Her body betraying her with every cum. Gradually, my pleasure subsided but Rachel seemed to beg for more. Her back arched, eyes rolled back, like trying to get one more orgasm out of herself.

"Oh such a good boy!" Lindsay said, "Such a good job cumming in your sister like that." She reached up and pet my cheek. Gave me a little kiss. "I'm so proud of you."

I looked down and the reality of what I'd done suddenly took hold of me. My little sister's cunt was bright red. A thin stream of my sperm was already leaking out of it. She was crying, hard. Weeping.

"Oh God. Oh..." Rachel mumbled, again and again. She reached down to her pussy and pulled out a palmful of sperm. Stared at it fearful.

Seeing her work was done, Lindsay got up from the bed.

"I'm going to try to go find, Nicky," she said, "I wonder where that boy got off to?"

I looked over at my sister and felt so ashamed. Awful. I climbed up into the bed and wrapped my arms around her. Held her tight. She didn't fight back. Just trembled in my arms.

"Oh Rachel," I said, "I'm so sorry. I don't know what came over me. I just..."

"It's OK," Rachel said, she looked up at me and smiled, "Lindsay's right. It was... It's only fair."

"Are you sure?" I asked.

Rachel leaned in and kissed me. "Is my loving brother holding me right now? Then yes. Everything is fine."

*

We cleaned everything up before the Callahans came home. All six of us sat down to dinner. It was the usual uncomfortable silence, but I found that comforting somehow.

Nick wouldn't even look in my direction the whole time. He seemed distant. Distracted. After dinner, he went into the TV room with his Dad. Lindsay, Rachel, and I marched upstairs. The girls went into their bedroom. There was no door to shut, but I felt it slam anyway.

I went and brushed my teeth by myself. Lay down in my sleeping bag. I didn't know what to do. The guilt and shame overwhelmed me. I heard the two girls talking. Just like every other evening. Only now, I was afraid of what they could be saying, rather than aroused by it.

Yet, for some reason, I couldn't help myself. I slipped out into the hallway.

"Well, you got what you wanted," Lindsay said, "Was it worth it?"

"Oh fuck yes," Rachel said, "I'm just so glad I got to share it with you. My best friend."

"You're sure this is OK?" Lindsay said, "I felt so terrible in that moment."

"OK?" Rachel said, "It went even better than I planned! Now I've got my brother's cock forever and you're free of stupid, useless Nick."

"I do feel kind of bad for my brother," Lindsay said.

"He was an asshole," Rachel said, "He treated you like crap and then couldn't even make you cum. I mean, come on. I think everybody here got what they deserved. You're a hell of an actor, though, I'll tell you."

"Me?" Lindsay said, "You were amazing. Your whole 'oh no don't do it to me' thing. I was starting to wonder if it really was true."

"Well we both get the award," Rachel said, "This is going to be so great."

"You were right this whole time," Lindsay said, "I mean, how did you even know he was listening all those times?"

Rachel looked up at the open door, like she could somehow see me standing in the hallway. Like her sight went right through the wood paneling. Through my body and right to my soul. It froze as it all dawned on me at once. This whole time it had been Rachel. Rachel who'd been pushing Lindsay to do these things. Rachel who'd known I was listening, pretended to be all innocent and afraid. Rachel who'd knocked up Lindsay on purpose and then tricked me into doing the same to my own sister.

I felt overwhelmed. My breath caught in my chest. My heart raced. I slumped back against the wall.

"I told you," Rachel said, "I know my big brother. He'll take such good care of both of us. Now if only someone with a big, hard dick would come in here and give us girls another full load. You know, just to make sure everything is all set.

I pictured Rachel and Lindsay sitting there, waiting for me. In that moment, I didn't care about how I'd gotten to this place. Only that I was there.

Rachel had me completely and I knew it. Even better, I found I was content with it in a way that I couldn't explain. Only enjoy. Without another word, I walked into Lindsay's bedroom and my crazy, incomprehensible, wonderful future.