I slammed my sister against the bedroom door the second she walked in from work. "You said you stopped taking the pill," I growled, yanking her skirt up.
"Tell me your cunt is ready for me to knock you up tonight."
Lindsay moaned and spread her legs. "It's been three weeks. I'm fertile as fuck. Put a baby in me, big brother."
I ripped her panties off and shoved two fingers straight into her dripping hole. She was soaked, slick dripping down her thighs already. I finger-fucked her hard and fast while I bit her neck. "Gonna fill this pussy so full of cum you won't be able to walk straight. Gonna breed my own sister."
She clawed at my belt, freeing my thick cock. "Do it. Fuck me raw. I want your load in my womb."
I spun her around, bent her over the bed, and drove my cock balls-deep in one thrust. Her tight walls gripped me like a fist. I didn't go slow. I pounded her like an animal, hips slapping against her ass, the wet sound of her pussy taking every inch loud and filthy.
"Harder," she begged. "Breed me. Make me pregnant with your kid."
I grabbed her hair and yanked her head back. "You want your brother to put a baby in you? Say it."
"Yes! Fuck your sister pregnant! Fill me up!"
I hammered her until my balls tightened, then buried myself to the hilt and unloaded. Thick ropes of cum blasted straight into her fertile cunt. I kept thrusting through it, pushing my seed deeper, making sure it stayed inside. When I pulled out, a creamy mess leaked out of her stretched hole, but I scooped it up and shoved it back in with my fingers.
"Keep that in there," I ordered. "We're not done."
I flipped her onto her back, spread her legs wide, and slammed back inside. Her tits bounced with every thrust. I sucked on her nipples while I fucked her, imagining them swelling with milk later. Lindsay wrapped her legs around me and clawed my back.
"Give me another load," she panted. "I want twins. I want you to ruin me."
I fucked her through two orgasms, her pussy milking me, before I came again, flooding her even deeper. This time I stayed inside, grinding against her clit until she came a third time, her walls pulsing around my cock.
We didn't stop there. I took her in the shower, bent over the sink, and finally on the floor with her riding me reverse cowgirl so I could watch my cum-slick cock disappearing into her. Every time I finished I made her hold her knees to her chest so gravity would keep my seed in her womb.
By morning she was a mess of dried cum and fresh loads, her belly slightly bloated from how much I'd pumped into her. She smiled lazily, hand on her lower stomach.
"I can feel it working already," she whispered. "Your sister's going to have your baby."
I rolled her onto her stomach and slid back inside her swollen, cum-filled pussy for one more round. "Then let's make sure."
