I walked in on my wife riding her boss's cock like a desperate slut. She was moaning his name, her tits bouncing, her pussy stretched around him while she told him how much better he fucked her than me. I stood there for ten seconds, dick soft from shock, then turned around and left without a word. No yelling. No fight. Just the door slamming behind me and the sound of her gasping when she finally noticed.
I drove straight to my sister's apartment. Mia was three years older, always the wild one in the family, the one who used to sneak boys into her room and laugh about it later. She opened the door in a tank top and shorts, took one look at my face, and pulled me inside.
"What the fuck happened?" she asked.
I told her. Straight up. No sugarcoating. "Caught Lisa getting pounded. She was begging for it. Said his dick was bigger."
Mia's eyes narrowed. She locked the door, walked over, and grabbed my belt. "Then fuck me. Right now. Use me to get back at that bitch."
She yanked my pants down and wrapped her hand around my cock, stroking it hard and fast until it stiffened. "You want revenge? Put it in your sister's cunt. Make it dirty."
I pushed her against the wall and ripped her tank top down. Her tits spilled out, nipples already stiff. I sucked one hard, biting just enough to make her hiss, then spun her around and bent her over the kitchen table. Her shorts came down easy. No panties. Her ass was round and firm, and her pussy was already wet when I shoved two fingers inside.
"Fuck, you're soaked," I growled.
"Because this is fucked up and I want it," she shot back. "Quit talking and fuck me."
I lined up and slammed into her in one thrust. Her cunt gripped me tight, hot and slick. I didn't go slow. I pounded her hard, the table legs scraping the floor with every thrust. Her ass rippled every time my hips slapped against it. She reached back and spread her cheeks wider, giving me deeper access.
"Harder," she demanded. "Make it hurt. Make me feel like the dirty sister who lets her brother wreck her pussy because his wife is a whore."
I grabbed her hair and yanked her head back, fucking her like a machine. Skin slapping skin. Wet sounds filling the room. She came first, cunt pulsing around my cock, juices dripping down her thighs. I didn't stop. I kept drilling until my balls tightened and I unloaded deep inside her, flooding her with thick ropes of cum.
We didn't talk after. She just turned around, dropped to her knees, and sucked me clean, licking every drop off my shaft while looking up at me with those same eyes that used to tease me growing up.
"Bedroom," she said when she stood. "We're not done."
I followed her.
She stripped the rest of the way and climbed onto the bed on all fours, ass up, my cum already leaking from her pussy. I climbed behind her and pushed back in, slower this time but just as deep. I reached under and rubbed her clit while I fucked her, making her moan into the pillow.
"Tell me how it feels," she panted.
"Like the best revenge fuck I've ever had. Your cunt's tighter than hers. Wetter. You want it more."
She pushed back against me, taking every inch. "Because it's wrong. Because you're my brother and you're using my hole to punish your cheating wife. Keep going. Fill me again."
I did. We switched positions—her on top riding me, then me on top with her legs over my shoulders so I could bottom out. She came twice more before I blew another load, this time pulling out and spraying it across her stomach and tits. She rubbed it into her skin like lotion, then licked her fingers clean.
We spent the rest of the night that way. Raw. No romance. Just filthy, repeated sex. I fucked her mouth until she gagged. I took her ass after she begged for it, working my cock into her tight hole while she fingered her cum-filled pussy. She called me "brother" every time she came, making the taboo sting hotter.
By morning my phone had twenty missed calls from my wife. I ignored them. Mia was on her back, legs spread, my cum dried on her thighs, smiling like she'd won something.
"Go home and tell her," she said. "Or don't. Either way, this isn't the last time you fuck me."
I left with her scent on me and her words in my head. My wife could keep her boss. I had a new outlet for revenge, and it was better, dirtier, and closer than she would ever know. Mia texted me before I reached the car: "Come back tonight. My ass needs more."
I answered with one word: "Yes."
