The door slammed open and there she was, legs spread on the bed, two fingers buried deep in her shaved cunt. "What the fuck, Lisa?" Mark growled, his voice low and rough. At 22, she knew better than to pull this shit in the house they still shared after their parents moved out. She was 20, old enough to know the rules, old enough to get punished for breaking them.
She didn't even try to cover up. Her fingers kept moving, slick and shiny. "Caught me thinking about your cock again, big brother. What you gonna do about it?"
Mark's belt was already coming off. "You want incest shit? Fine. But you're getting punished first." He yanked her across his lap before she could react. Her bare ass was pale and round, perfect for what he had planned. The first smack landed hard, the crack echoing off the walls. Lisa yelped, then moaned when the sting spread.
"Count them," he ordered, voice thick with anger and something hotter. "Every slap for every filthy thought you had about your own brother."
"One," she gasped. The second smack was harder, right on the same spot. Her pussy clenched visibly, a string of wetness dripping down her thigh. "Two. Fuck, Mark, harder."
He didn't hold back. By ten her ass was bright red, handprints blooming across both cheeks. She was grinding on his thigh now, soaking his jeans. "You like getting punished for wanting my dick?" he snarled, sliding two fingers between her legs without warning. She was dripping, hot and tight. He pumped them rough, curling against her spot until she shook.
"Yes," she hissed. "Punish this slutty sister cunt. Spank it, fuck it, whatever you want."
Mark stood her up, bent her over the edge of the bed, and shoved his pants down. His cock sprang free, thick and veined, already leaking. He didn't ease in. One thrust buried him balls-deep in her soaked pussy. Lisa screamed into the mattress, pushing back for more. "That's it, take your punishment fuck," he grunted, gripping her punished ass hard enough to leave bruises. Every slap of his hips against her red skin made her whimper.
He pulled out and flipped her onto her back, legs over his shoulders. "Look at me while I fuck the incest out of you." His cock slammed back in, deep and relentless. Lisa's tits bounced with every thrust, nipples hard. She reached down to rub her clit but he slapped her hand away. "No. You come when I say."
He fucked her like he hated her for wanting it, long punishing strokes that bottomed out every time. Sweat dripped off his chest onto her stomach. When he pulled out again she whined, empty, until he flipped her back onto all fours and spread her ass cheeks. "This hole next," he said, spitting on her tight ring. His thumb pushed in first, then the head of his cock. It burned, stretched, but she pushed back anyway.
"Fill your sister's ass as punishment," she begged, voice raw. He sank in slow at first, then faster once she adjusted. His balls slapped her pussy with every thrust. One hand reached under to pinch her clit while the other smacked her already-bruised ass. Lisa came hard, squirting around nothing, ass clenching on his cock.
Mark didn't stop. He kept pounding until his own orgasm hit, flooding her ass with thick ropes of cum. He stayed buried until he softened, then pulled out and watched it leak. "Clean it," he ordered. She turned around on shaky knees and sucked him clean, tasting her ass and his load mixed together.
They collapsed on the bed, breathing hard. Mark's hand rested on her sore ass, possessive. "Next time you want incest, you ask for it. Otherwise this is what you get."
Lisa smiled against his chest, already planning her next "punishment."
