Fuck, I knew it was wrong the second I walked into her apartment that night, but my cock was already hard thinking about it. My little sister, twenty-three years old and built like a fucking wet dream, had been texting me all week about how she wanted it bare. No condoms, no pulling out. Just straight-up incest fertilization, her words. She wanted my cum deep in her pussy until it took.
I kicked the door shut behind me. "You sure about this, Mia?" I asked, even though my hands were already on her hips.
She grabbed my belt and yanked it open. "Shut up and breed me, big brother. I've been dripping all day thinking about your load putting a baby in me."
Her tank top came off in one pull. Those heavy tits bounced free, nipples already stiff. I shoved her against the wall and sucked one into my mouth while my fingers went straight down her shorts. She was soaked. No panties, just slick, shaved cunt lips and a swollen clit begging for attention.
"Jesus, you're ready," I growled, two fingers sliding into her tight hole.
"Been fingering myself since lunch," she panted. "Thinking about you pumping me full. Filling my womb with your cum so I get pregnant from my own brother."
That dirty talk lit me up. I spun her around, bent her over the couch, and ripped her shorts down. Her ass was perfect, round and pale, and her pussy lips were puffy and shiny with juice. I dropped my pants, spit on my hand, and rubbed the head of my thick cock up and down her slit.
"Tell me you want it," I said, pressing just the tip inside.
"Put it in," she begged. "Fuck me raw and cum inside me. Make me pregnant."
I slammed home in one thrust. She was tight as hell, gripping every inch. I started pounding right away, balls slapping her clit, the wet sound of incest sex filling the room. Mia moaned like a slut, pushing back to take me deeper.
"Harder," she gasped. "Knock me up. I want your sperm swimming up to my eggs."
I grabbed her hair and fucked her like an animal. Skin slapping, her tits swinging, my cock stretching her cunt wide open. Every time I bottomed out she whimpered, "Yes, breed me, breed your sister."
I lasted maybe ten minutes before the urge hit. My balls tightened and I buried myself to the hilt, flooding her. Thick ropes of cum pumped straight into her womb. She came with me, pussy milking every drop, screaming my name while her walls fluttered around my shaft.
But that wasn't enough. Not for what she wanted. I pulled out, watched my load start to leak, then flipped her onto her back on the floor. I shoved back inside while she was still twitching, fucking my own cum deeper.
"Keep it in there," I ordered, grinding slow and deep. "Don't waste a drop."
She wrapped her legs around me. "More. Give me another load. I want twins from this filthy incest fuck."
I gave it to her. We went at it for hours. On the couch, in the shower, bent over the kitchen table. Every position ended with me dumping another hot, thick creampie right against her cervix. By the time we collapsed, her pussy was a mess, puffy, red, and overflowing with my seed. She kept two fingers plugged inside herself, holding it in.
"Think it took?" she whispered, smiling like a satisfied whore.
I rolled on top of her again, already hard. "Only one way to make sure."
We fucked until morning, raw and messy, my cum leaking out around my cock every time I thrust back in. When the sun came up she was on her back with her knees to her chest, my final load slowly dripping toward her fertile womb while she rubbed her clit and whispered how full she felt.
That was the start. Every night after that she called me over for more incest fertilization. No protection, just my sister begging for her brother's cum until her belly started to swell.
And fuck if that didn't make me want to keep filling her even more.
