I came home from college that summer and everything changed the second I saw my sister Lisa again. She had always been curvy, but now at twenty-two she was a full-blown BBW with massive tits that strained every shirt, wide hips, a soft round belly, and an ass so fat it jiggled when she walked. I tried not to stare the first night, but when she bent over to grab something from the fridge in those tiny shorts, her cheeks spilled out and I knew I was fucked.
We had the house to ourselves for two weeks while our parents were gone. Lisa caught me staring that first evening and just smirked. "You like what you see, little brother?" she asked, turning slowly so I could take in every inch of her soft, heavy body. I didn't answer with words. I walked up, grabbed two handfuls of her huge ass, and squeezed hard. She moaned low and pushed back against me.
"Been waiting for you to notice," she said, voice already husky. "My pussy's been wet thinking about you seeing me like this."
I yanked her shorts down right there in the kitchen. Her thick thighs rubbed together and her fat ass was pale and perfect, dimpled and soft. I dropped to my knees and buried my face between her cheeks, licking her asshole first because I wanted to be nasty about it. Lisa gasped and spread her legs wider, letting my tongue push inside while my hands kneaded her heavy cheeks. Then I moved lower, dragging my tongue through her wet slit. She tasted sweet and musky, her fat pussy lips swollen and dripping. I sucked her clit and she started grinding back on my face, her belly and tits shaking with every movement.
"Fuck, eat that pussy," she groaned. "Been needing a real tongue on it."
I stood up, dropped my pants, and shoved my cock straight into her from behind. She was tight despite how thick she was, her walls gripping me as I sank balls-deep into her wet cunt. I fucked her hard and fast, slapping her ass so it rippled, watching the red handprints form on her pale skin. Lisa braced against the counter and pushed back to meet every thrust, her big tits swinging free once I pulled her top off.
"Harder," she begged. "Fuck your sister's fat pussy like you mean it."
I slammed into her until she came, her whole body shaking, juices running down her thick thighs. I didn't pull out. I kept pounding until I unloaded deep inside her, filling her up while she moaned my name.
That was just the start. Over the next days we fucked everywhere. In the shower I soaped up her huge tits and slid my cock between them, fucking her cleavage while she licked the head every time it poked through. She got on her knees and sucked me sloppy, gagging on my length, spit running down her chin onto her massive breasts. I came on her face and tits, watching it drip over her soft curves.
Nights we spent in her bed. She'd ride me, her heavy body bouncing, belly and tits slapping against me while her fat ass slammed down on my cock. I'd grab handfuls of her ass and spread her cheeks, watching my dick disappear into her stretched pussy. Sometimes I'd flip her onto all fours and pound her ass, working lube into her tight hole until I could fuck it deep, her cheeks clapping loud with every thrust. She loved it dirty, begging me to call her my fat slut, my thick sister whore, while I stretched both holes.
One afternoon she had me fuck her on the living room floor, her on her back with legs spread wide so I could watch every jiggle of her body. I sucked her big nipples while I thrust slow and deep, then faster until she squirted around my cock. I pulled out and came all over her soft belly and pussy, then pushed back inside to feel my mess mixing with hers.
By the end of the two weeks we didn't bother hiding it. She slept in my bed, waking me up with her mouth on my cock or by sitting her fat ass on my face. We talked about how wrong it was but how good it felt, how her thick body was built for exactly this kind of nasty fucking. When our parents came home we kept sneaking it, quickies in the garage or late at night when everyone was asleep, her muffling moans into a pillow while I pumped load after load into her greedy holes.
It never stopped being raw and filthy. Every time I saw her heavy tits or that massive ass I got hard, and every time she spread for me like the perfect incest BBW fuck she was.
