the drawn line is already thin

John slammed his bedroom door harder than he meant to and dropped the towel like it burned.

His cock was still half-hard, slick and twitching, the ghost of that orgasm still pulsing through him. A last lazy bead of cum welled at the slit and slid down the shaft. He braced both hands on the dresser and stared at his own reflection, breathing like he’d just sprinted a mile. His face was flushed. His pupils were blown. The towel on the floor was already spotted where the head of his cock had dragged across it.

He’d been edging the whole run. Every stride, every bounce of his cock against his thigh, he’d been thinking about Lila’s hand in the kitchen, the way she’d weighed him through his sweats, Maya’s thighs on the island and the wet spot on her shorts, Sadie’s soft little “morning, big brother” and the way her boy shorts had ridden up between her cheeks. By the time he stepped into the shower he was already leaking, fist working slow and mean just to take the edge off so he could function the rest of the day. He’d told himself that was all it was. Relief. Maintenance. Not them.

Then the door opened.

And there she was—his little sister—on her knees, shirt shoved up over her tits, ass in the air, that pretty pink cunt spread open and glistening like it was begging for exactly what he was trying not to give it. Steam on her skin. Nipples tight. Knees apart on the bathmat. Every time she reached forward her folds parted and he could see everything: the swollen lips, the shiny hole, the way it twitched like it knew he was watching. The sight hit him so hard his knees almost buckled. His fist had already been moving. It only moved faster. One more second—one more throb—and he wouldn’t have come on the wall.

He would have stepped out of that stall, grabbed a fistful of Sadie’s hair, and buried himself to the hilt in one brutal thrust. No warning. No condom. No hesitation. Just raw, wet heat and the filthy, animal need to pump her full until she was dripping his cum down her thighs and crying how good it felt to get knocked up by her own brother. He could still feel the phantom of it: her cunt gripping him, the slap of his hips on her ass, the way she would have pushed back and taken it.

The thought alone made his cock jump against the dresser, a fresh bead of precum smearing the wood. He was hardening again already, thick and angry, the first load barely finished.

He squeezed his eyes shut.

“Fuck… fuck, Sadie…”

He’d been so close. The only reason she wasn’t currently face-down on the bathmat with his cock rearranging her guts was pure timing. His orgasm had ripped through him a heartbeat before the last thread of control snapped—hot, shameful, painting the tile in thick white ropes while he stared at his sister’s open cunt and bit down on a groan that still escaped. If he’d lasted even three more strokes he would have been balls-deep in his own blood, hips slamming, snarling the filthiest things while he tried to breed her right there on the bathroom floor. He could still see it when he blinked: her face-down, ass-up, his cum leaking out of her around his cock.

And the worst part—the part that made his stomach twist with heat instead of shame—was how badly he’d wanted it. How natural it had felt. How right. How his body had voted before his mouth could even form get out.

Down the hall he could already hear soft, wet sounds and low female laughter drifting from the bathroom. They were still in there. Tasting him. He knew what that sound was. Tongues on tile. Fingers sharing what he’d left on the wall. Talking about him. Planning the next time. The thought of Lila feeding his cum into Maya’s mouth, of Sadie licking a stripe off the stall where he’d painted it while staring at her, made his cock throb hard enough to slap against the dresser drawer.

John dragged a hand down his face, then down his stomach, and wrapped it around himself again without meaning to. Still heavy. Still aching. Still slick from the shower and his own mess. He gave himself one slow, punishing stroke and had to stop, jaw locked, because even that felt like agreeing.

He was running out of rope.

And his sisters knew it.