I [23F] made my sister’s[26F] boyfriend [26M] cheat on her

Disclaimer: All characters are over 18.

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So, this all happened last Friday night/Saturday morning. I’ll try to keep it as detailed as I can.

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Some context – I, and my sister and our other siblings all live at home still. Her boyfriend stays over some weekends. This weekend just gone, our parents took our younger siblings away for the week, so it was just the 3 of us at home.

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It was a normal Friday night – I mostly kept to myself in my room while they were here. But obviously with my parents and most of my siblings gone, they were feeling extra brave, and I think they were also a bit drunk. From 11PM onwards, I could hear them fucking for at least 2 hours. Foreplay, oral, fucking, I heard it all. The walls are thin. Ashamedly, it turned me on a bit. I haven’t been fucked in a while and hearing the grunting sounds her boyfriend made, especially every time he came, really got me going.

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I remember listening to her gagging while she sucked his cock. Even though she was my sister, it turned me on. I turned my lights off and I lay in my bed, naked. I rubbed my clit while I listened to him moaning and grunting, listened to her gag, and I eventually came while listening to them. I fell asleep pretty peacefully after that.

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I awoke early on Saturday morning and went for a shower. I got out and picked my phone up, noticing I had a text from my sister. “Hey – I got called into work. Please just stay in your room and don’t bother Mark, okay? I’ll be home at around 6PM”. The text really annoyed me. What made her think I’d want anything to do with her boyfriend? She didn’t mean to, but she had a way of just pissing me off. I figured it was a sister thing.

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Mark wasn’t someone I was typically attracted to, but I wanted to get back at my sister. I wasn’t planning on doing anything major, I just wanted to tease him a little bit.

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Still wearing my towel, I walked from my room, straight into my sister’s room, without knocking. He was in her bed, awake, under the blankets. “Hey, sorry to just barge in, I’m looking for some clothes of mine that Chloe borrowed.” I said, not giving him a chance to say anything.

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I pretended to rummage through her wardrobe, and took a couple of t-shirts, before turning to him. He looked a bit alarmed. I had my towel lowered slightly so he could see some of my cleavage, and noticed him looking. Perfect.

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“Do you like to stare?” I asked him, smiling. His face flushed red, clearly embarrassed.

“Sorry, I just, er, I wasn’t expecting you to be… naked.” He had said. “Or almost naked, anyway.”

I laughed at him, shaking my head. “You don’t have to be sorry. I heard you guys last night. Quite the performance, if I do say so myself.” I said, and slowly stepped closer towards the bed. He looked at a loss for words.

“Can I ask you something?” I asked him, tilting my head to the side. He nodded his head.

“Do you ever think about me while you’re fucking my sister?” I said, and now I sat at the edge of the bed.

His face grew redder, and I already had my answer. “Of course not!” He said, quite defensively.

“Are you *sure* about that?” I asked, and I loosened my towel, throwing it to the side of the room. I was sitting at an angle so he could only see me from the side, but he was now able to see my tits. “I like honesty, you know.”

“I… Sometimes I do, yeah.” He finally admitted.

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I laughed, and I thought about leaving then and there. I had teased him enough, and this was enough revenge on my sister. But I felt a warmth between my legs as I thought about him, fucking my sister but thinking about me. I repositioned onto my knees on the bed.

“Good boy. Thank you for being honest with me.” I said, and I had slowly started to crawl towards him. He looked like a deer caught in headlights. “I like that you think about me.” I said, pulling the duvet back from him. His cock was erect. Nothing special, but nothing bad. I’d guessed around 6 inches, and decently thick.

“I listened to you fucking her last night.” I said to him, as I crawled between his legs, which he had started to slowly spread a bit wider for me. “And when I could hear her sucking your cock, I fantasised about doing it myself, and fingered myself until I came.” I said, with a smirk. He still hadn’t spoken since his admission.

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“Can I suck your cock?” I asked him. I could see him fighting a battle inside of his mind. He wanted to say yes, but he obviously had doubts. “I promise I won’t tell my sister.” I said, with a warm smile. He nodded his head, slowly.

“Thank you.” I said to him, and I bent down on my arms and knees, in between his legs. I smiled up at him as I licked around the head of his cock, teasing him. There was already some precum.

“Mm.” I said, and I wrapped my lips around the head, and dragged my tongue across his frenulum, which he seemed to love.

I pulled back, and I kissed down his hard cock, and started to suck his balls, using my right hand to stroke his cock. I was so fucking wet now. I hadn’t been with someone for so long, and here I was, sucking off my older sister’s boyfriend. I stopped jerking his cock and I moved my hands under his legs, motioning for him to put them up a bit.

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I started to lick under his balls, and noticed his back arching a little bit. I pulled back, and looked up at him. “Just stop me if you get uncomfortable, okay?” I said to him. I smiled at him and then went back to licking, and as his back arched, I took my chance, and went lower. I started to tongue his asshole and he moaned, loudly.

He twitched and grunted and my hand went to his cock while I tongue fucked his ass. I stroked him slowly while I did it, moaning against him as I felt myself dripping wet.

“I’m gonna cum.” He grunted, and I let go of his cock, and pulled back.

“Not yet!” I said, shaking my head. I took a few seconds to catch my breath, and then I straddled myself over him, with a smile. “Ready?” I asked him, and he nodded his head.

He held his hard cock still and I lowered myself onto it, moaning as I felt each inch fill me. “Fuck… Fuck.” I said, resting on it for a second, my eyes closed. I grabbed his hands and placed them on my tits, and I started to rock my hips on him, riding his cock.

He moaned loudly, and I knew after the blowjob and rimjob, he wouldn’t be able to last long. I looked down into his eyes as I rode his cock, feeling nothing but pure lust inside of me.

“I’m… Fuck. I’m close.” He said, almost sounding strained. I could tell he was trying not to cum.

“It’s okay.” I moaned, and I bent further forward, letting my tits rest in his face. “You can cum. Please, cum for me! Cum!” I moaned, and I rode his cock as fast as I could, feeling his hot breath against my bare skin as his load shot inside of me. “Mmmm, fuck. Good. Good boy.” I moaned, running my fingers through his hair as he groaned against me. “That’s my good boy.” I said, and I kissed him on the forehead.

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I got off of him, and he lay there, panting. As I stood up, I could feel his cum, mixed with my own juices, dripping down my thighs. “I need to shower again.” I said, with a sigh. I looked towards him, and smiled. “Thanks for letting me do that. I’ll see you later.” I said, and I walked out of the room.

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We haven’t spoken since. Like my sister requested, I left him alone after that, and he left early on Sunday. I don’t think she suspects anything, as everything has been normal since that day. I don’t think I’ll ever fuck Mark again, but I was glad I could get my own back on my sister.

Source: reddit.com/r/gonewildstories/comments/11xrjkv/i_23f_made_my_sisters26f_boyfriend_26m_cheat_on