I came home from work and caught my sister stroking her fat cock on the couch. She had her legs spread wide, that thick dick standing straight up in her fist, the head shiny with precum. "Don't just stand there, sis," she growled. "Get over here and suck it."
We were both adults, no excuses. I'd known for years she was futa but we'd never crossed the line until that night. I dropped my bag, kicked the door shut, and walked straight to her. I got on my knees between her thighs and wrapped my lips around the head of her cock. It tasted salty and hot. She grabbed my hair and pushed deeper, making me gag on the first thrust.
"Fuck, your mouth feels better than I imagined," she said, voice low and rough. She pumped her hips, sliding that veiny shaft over my tongue until my nose pressed against her smooth mound. Spit ran down my chin. I reached up and cupped her heavy balls, squeezing them while I bobbed my head faster. She moaned loud and filthy, telling me exactly how she wanted it: deeper, tighter, messier.
After a few minutes she pulled me off and stood up. "Strip. Now." I yanked my clothes off in seconds. She bent me over the arm of the couch, kicked my feet apart, and spat on my pussy. One thick finger pushed inside, then two. "You're already dripping. You want your sister's cock that bad?"
"Yes," I panted. "Fuck me with it."
She lined up and shoved in hard. The stretch burned in the best way. Her cock was bigger than any toy I'd used, thick and rigid, forcing my walls open. She didn't go slow. She fucked me like she hated me and loved me at the same time, hips slapping loud against my ass. Every thrust knocked the breath out of me. I reached down and rubbed my clit in fast circles while she pounded me.
"Take it, little sis," she grunted. "Take every inch of your sister's dick." She grabbed my hips and yanked me back onto her, bottoming out again and again. The wet sound of her cock sliding in and out filled the room. I came hard, legs shaking, pussy clenching around her. She didn't stop.
She kept driving through my orgasm until I was whimpering.
She pulled out, flipped me onto my back on the couch, and climbed over me. She fed her cock back into my mouth so I could taste my own cum on it. Then she straddled my chest and jerked herself fast, aiming at my open lips. Thick ropes of cum shot across my tongue and face. I swallowed what I could and licked the rest off her fingers when she fed it to me.
We didn't talk much after that. We just moved to her bed. She fucked me twice more that night, once with me riding her and once with my legs over her shoulders while she pinned my wrists. Every time she came inside me she made sure I felt it, grinding deep so none leaked out right away. By morning my pussy was sore and swollen and I still wanted more.
We kept it going after that. Some nights she woke me up by sliding into me from behind while I was half-asleep. Other times I dropped to my knees the second she walked through the door. We never called it anything fancy. It was just us, raw and dirty, family crossing every line we could find and loving how wrong it felt. She still fucks me the same way now, hard and direct, telling me I'm her favorite hole. I wouldn't have it any other way.
