The bombs had dropped months ago, turning the world to ash and ruin. My sister Lena and I had been lucky, holed up in an old bunker outside what used to be the city. At twenty-eight, she was two years older than me, tough as nails from years of surviving on the road together. We shared everything now: food, water, the single narrow cot, and the heavy silence that came with knowing we were the last of our bloodline.
One night the generator failed, plunging us into darkness. The air grew thick with heat from the sealed doors. Lena stripped down to her tank top and panties, sweat glistening on her skin. "Come here, little brother," she said, voice rough. "Body heat's all we've got."
I climbed in behind her, my cock already half-hard from the way her ass pressed back against me. She didn't pull away. Instead, she reached back and grabbed my shaft through my shorts. "Fuck, you're stiff. Been thinking about this too?"
"Yeah," I grunted, sliding my hand under her top to squeeze her tits. Her nipples were hard pebbles. I pinched them hard, and she moaned, pushing her ass harder against my dick. "We're all that's left.
No rules anymore."
Lena turned, yanking my shorts down. My cock sprang free, thick and veined. She wrapped her fingers around it and stroked once, slow and filthy. "This cock's been teasing me for weeks. Time to use it." She shoved her panties aside and straddled me, rubbing her wet pussy along my length. Her slit was hot, dripping, and she sank down without warning, taking every inch in one thrust.
I groaned as her tight cunt gripped me. She rode hard, hips slamming down, tits bouncing in my face. I sucked one nipple into my mouth, biting just enough to make her curse. "Harder, you bastard. Fuck your sister like you mean it."
I flipped her onto her back, spreading her legs wide. My cock drove back in balls-deep, pounding her soaked hole with wet, slapping sounds. Lena clawed my back, legs locked around me. "Deeper. Split me open. Fill your sister's pussy with that load."
Sweat slicked our bodies as I hammered into her. Her walls fluttered, squeezing me every time I bottomed out. She came first, cunt pulsing, juices coating my shaft and balls. "Don't stop," she gasped. "Keep fucking me."
I pulled out, flipped her onto all fours, and slammed back inside. Her ass cheeks rippled with each thrust. I reached around to rub her swollen clit, feeling her drip down my fingers. "You like your brother's cock wrecking this hole?" I growled.
"Fuck yes," she snarled back. "Cum in me. Breed me in this shithole world."
My balls tightened. I buried myself to the hilt and unloaded, thick ropes of cum flooding her pussy. She milked every drop, grinding back until I was spent. We collapsed together, my cock still twitching inside her, cum leaking out around the base.
Later, in the dim light, she sucked me clean, tongue lapping our mixed mess. Then she climbed on again, slower this time, riding me until we both came once more. In the wasteland, nothing else mattered but the heat between us, raw and endless. We fucked until dawn, two survivors claiming the only pleasure left.
