We had always danced around it, my sister and me. At twenty-two and twenty-four, we were adults who knew better, yet the house we shared after our parents moved away felt too small for the heat that built every time she brushed past me in the hallway. That night started with cheap whiskey and old arguments about who got the bigger bedroom. One drink turned into three, and suddenly her hand stayed on my thigh longer than it should have.
"Fuck it," she muttered, eyes locked on mine. "We've both thought about it."
I didn't answer with words. I grabbed her by the waist and pulled her onto my lap. Her shorts were thin, and I could feel the heat of her pussy pressing against my cock through my jeans. She ground down hard, and a low groan escaped her throat. "This is so fucking wrong," she whispered, but her hips kept moving, rubbing her clit against the ridge of my dick.
I yanked her tank top up and sucked one nipple into my mouth, biting just enough to make her gasp. Her fingers fisted in my hair. "Suck it harder, you bastard. Make it hurt." I switched to the other breast, leaving wet trails, while my hand slid inside her shorts and found her already soaked. Two fingers pushed straight into her tight cunt, and she bucked against them.
"Oh god, yes. Finger-fuck your sister like you mean it." The word "sister" made my cock throb painfully. I pumped my fingers faster, thumb circling her clit, listening to the wet sounds fill the living room. She came fast and loud, thighs shaking, juices coating my hand.
We didn't stop. She dropped to her knees, ripped my jeans open, and swallowed my cock in one greedy motion. Her tongue worked the underside while she took me deep, gagging but not pulling back. Spit ran down my balls. "That's it, take your brother's dick," I growled, holding her head and fucking her throat. She moaned around me, the vibration sending sparks up my spine.
When I couldn't take it anymore, I hauled her up, bent her over the couch, and tore her shorts down. Her ass was perfect, pale and round. I slapped it once, twice, watching the red bloom. "You want this cock inside you? Say it."
"Fuck me," she begged. "Shove that forbidden dick in my pussy right now."
I slammed into her in one thrust.
She was dripping, tight, and hotter than anything I'd ever felt. We both froze for a second, realizing what we had done. Then she pushed back. "Don't stop. Pound me."
I did. Hard, fast, skin slapping skin. Each stroke bottomed out against her cervix, and she met every one, cursing and moaning. "Deeper, fuck your sister deeper. Fill me up." My balls slapped her clit with every drive. I reached around and rubbed her swollen nub until she screamed and clenched around me, milking my cock.
I pulled out just long enough to flip her onto her back on the floor. Her legs spread wide, pussy glistening and swollen from use. I drove back in, watching my shaft disappear into her over and over. She grabbed my ass, pulling me harder. "Come inside me. I want to feel my brother pump his load into my cunt."
That did it. I exploded, thick ropes of cum flooding her, overflowing and dripping down her ass crack. We stayed locked together, breathing ragged, the reality of what we'd done settling like smoke.
Later, in her bed, we didn't talk about stopping. She rode me slow and deep while I sucked her tits, both of us whispering the dirtiest things we could think of. "We're so fucked up," she panted. "And I never want to stop." By morning we had used every room in the house, each orgasm sealing the secret tighter. The forbidden taste only made us hungrier for more.
