I slammed the front door behind me after another bullshit shift at the warehouse, sweat still clinging to my skin. Mom and dad were gone for the weekend, leaving just me and my sister Leah in the house. She was twenty-one, same as me, and lately the way she looked at me had turned electric. Leah was sprawled on the couch in nothing but an old tank top and tiny shorts, legs spread like she owned the place. Her eyes locked on mine the second I walked in.
"Long day, big brother?" she asked, voice low and teasing.
I dropped my bag and stared. "You have no fucking idea."
She patted the cushion next to her. "Come sit. TV's on but it's garbage."
I sat. Close. Too close. Our thighs touched. Heat poured off her. Leah shifted, pressing her hip against mine, and I felt my cock twitch in my jeans. We had been dancing around this for months, ever since that drunk night we admitted we both got off thinking about each other. Incest. Taboo as hell. But here we were.
She leaned in, whispering, "Remember what you said last week? About wanting to grind on me without taking anything off?"
My hand landed on her bare thigh. "Yeah. Dry hump till we can't stand it."
Leah climbed onto my lap without another word. She straddled me, facing me, her crotch settling right over the growing bulge in my pants. She was already warm through those thin shorts. I grabbed her hips and pulled her down harder. We started slow, rocking. Her pussy rubbing along the length of my cock through two layers of denim and cotton. The friction was rough, perfect, building fast.
"Fuck, Leah," I growled. "You're soaking already."
She moaned and ground harder, rolling her hips in tight circles. "Been wet thinking about this all day. Your big dick pressed against my clit. No fucking, just this dirty dry humping like we used to do when we were younger and too scared."
I thrust up to meet her. The couch creaked. Her tank top rode up and I yanked it higher, exposing her tits. They bounced with every grind. I leaned forward and sucked one nipple into my mouth, biting just enough to make her gasp. She rode me faster, dry humping like her life depended on it. The pressure on my cock was insane, trapped, throbbing, leaking pre-cum into my boxers.
"Don't stop," she panted. "Rub that cock right on my pussy. Make me come like this."
I gripped her ass with both hands and worked her back and forth, dragging her soaked shorts over my hard shaft. The head of my dick kept catching on her clit through the fabric. Leah's breathing turned ragged. She buried her face in my neck, biting down as she humped faster, harder, the dry friction turning slick from how wet she was getting.
"Goddamn, sis," I muttered. "Your cunt feels so fucking hot even through clothes. Keep grinding. Use me."
She came first. Her whole body shook, thighs clamping around me, hips jerking in short, desperate thrusts while she whimpered my name. I didn't let up, kept dry humping through her orgasm, feeling every pulse. When she finally slowed, she reached down between us and squeezed my cock through my jeans.
"Your turn. I want to feel you blow in your pants."
Leah slid off just long enough to turn around, then settled back onto my lap facing the TV. Reverse cowgirl grind. Her ass cheeks spread over my bulge. She leaned forward, bracing on my knees, and started bouncing and rubbing in earnest. The new angle let my cock slide along her pussy lips from behind, still fully clothed. Every downward press mashed her against me.
I reached around and grabbed her tits again, pinching her nipples while I bucked up into her. The dry hump turned frantic. Sweat slicked our skin. The room filled with the sound of fabric rasping and heavy breathing. I was close, balls tight, cock aching from the relentless pressure.
"Right there," I groaned. "Don't you dare stop, Leah. Dry fuck your brother till he fills his shorts."
She slammed back harder. One more roll of her hips and I exploded. Hot cum pulsed out, soaking my boxers, trapped against her pussy through all the layers. I kept thrusting through it, smearing the mess between us as she kept grinding, milking every drop with that perfect dry hump rhythm.
We stayed like that, breathing hard, her still sitting on my softening cock.
Leah turned her head and kissed me over her shoulder, tongue sliding deep.
"Next time," she whispered, "we do it with less clothes. But tonight we keep it just like this. Filthy. Incest dry hump till morning."
I was already getting hard again.
