I came home late from the bar, half-drunk and horny as hell, and there she was on the couch in nothing but a tiny tank top and panties. My sister, Lena, twenty-three and built like sin, legs spread just enough that I could see the wet spot on her crotch. We had the house to ourselves for the weekend, parents gone, and the air already felt thick with something we had both been ignoring for years.
"Fuck, you look good," I said, dropping my keys and staring.
She looked up from her phone and smirked. "You gonna stand there or come over here and do something about it?"
That was all it took. I crossed the room in three steps, grabbed her by the hair, and kissed her hard, tongue shoving into her mouth. She tasted like mint and beer. Her hand went straight to my crotch, squeezing my cock through my jeans until it was rock hard.
"Been wanting to fuck you on this couch for months," I growled against her lips. I yanked her tank top up and sucked on her tits, biting the nipples until she moaned. She unzipped me, pulled my cock out, and started jerking it fast and rough.
I shoved her panties aside and pushed two fingers straight into her cunt. She was soaked, dripping down my hand. "Jesus, you're fucking wet for your brother."
"Shut up and fuck me," she hissed.
I flipped her onto her stomach on the couch cushions, yanked her ass up, and slammed my cock into her from behind. No slow start, just hard, deep thrusts that made the couch creak. Her pussy gripped me tight, hot and sloppy. Every time I bottomed out she grunted and pushed back harder.
"Fuck yes, pound that cunt," she said, voice muffled in the pillow. I slapped her ass red, held her hips, and fucked her like I hated her. Skin slapping, wet sounds filling the room, her juices running down my balls.
I pulled out and flipped her again so I could watch her face while I fucked her. Legs over my shoulders, cock buried to the hilt. She reached down and rubbed her clit fast while I drilled her. "Gonna come on your dick," she warned, and then she did, cunt pulsing and squirting a little around my shaft.
I didn't stop. I kept pounding through her orgasm until my own hit, and I pulled out just in time to shoot thick ropes across her stomach and tits. She rubbed it into her skin like lotion, then licked her fingers.
We weren't done. Ten minutes later she was on her knees on the floor in front of the couch, sucking me back to full hardness, gagging on it, spit everywhere. I fucked her face until tears ran down her cheeks, then bent her over the arm of the couch and took her ass. She screamed when I pushed in, but she pushed back, taking every inch.

"Harder, fuck your sister's asshole," she begged. I gave it to her, raw and relentless, one hand in her hair, the other reaching around to finger her cunt again. She came twice more before I filled her ass with cum.
We stayed on that couch all night. Different positions, her riding me reverse, me on top choking her lightly while I fucked her missionary, both of us talking filthy the whole time. "Your cock feels better than any boyfriend's," she said at one point. "Your cunt's tighter than any girl I've fucked," I answered.
By morning the cushions were stained and we were sore, but we knew we'd be right back there the next night.