The house was silent after midnight.
Their parents were asleep upstairs. The only light came from the low lamp in the living room. Isla sat on the couch in an old hoodie that barely covered the tops of her thighs. She wasn’t wearing anything underneath.
Her younger brother, Theo, walked in from the kitchen with a glass of water and stopped when he saw her.
His eyes dropped to her bare legs and stayed there.
“You’re still up,” he said quietly.
Isla didn’t look away. “Couldn’t sleep.”
Theo set the glass down. He was thirty. She was thirty-three. They had lived under the same roof most of their lives, but tonight the air felt different.
“You’ve been staring at me all evening,” Isla said. “Every time I moved. Don’t pretend you weren’t hard.”
Theo’s jaw flexed. “Isla—”
“I know you’ve jerked off thinking about fucking me.” Her voice was soft but steady. “I’ve heard you. Late at night when you thought the house was empty. I’ve touched myself listening to it.”
The space between them vanished.
Theo crossed the room in three steps, grabbed her face, and kissed her hard. Isla moaned into his mouth and shoved her hands under his shirt. He backed her against the couch, yanked the hoodie up, and filled his hands with her bare tits.
“These fucking tits,” he growled against her lips. “I’ve come so many times imagining sucking on them while I bury my cock in my own sister.”
Isla arched into his hands. “Then stop imagining and do it.”
Theo dropped to his knees, shoved the hoodie higher, and buried his face between her thighs. The first long lick through her already-wet folds made her gasp. He groaned like a man starving.
“Christ, you taste filthy. Sweet sister cunt dripping for her brother. I’m gonna eat this pussy until you come on my tongue, then I’m gonna stretch it open on my cock.”
He licked her open, tongue fucking into her while two thick fingers pushed inside. Isla’s hand fisted in his hair as he sucked her clit hard.
“That’s it—eat your sister’s cunt. Fuck, Theo, your tongue feels so good—”
He added a third finger, curling them, and kept sucking until she came hard, thighs shaking around his head, a broken cry she tried to muffle against her wrist. He didn’t stop. He licked her through it, then stood, wiped his mouth, and freed his cock.
Isla stared, eyes dark. “God, you’re thick. I want that wrecking me. I want my brother’s cock splitting my pussy open.”
Theo rubbed the leaking head through her folds. “Beg for it.”
“Please fuck me. Please put your cock in your sister’s cunt and ruin me.”
He thrust in to the hilt in one hard stroke.
Isla cried out softly. Theo groaned, forehead dropping to hers.
“Fucking hell—your pussy is strangling me. Tightest cunt I’ve ever felt and it belongs to my own sister. I’m never giving this up.”
He started fucking her in deep, punishing strokes. The wet slap of skin filled the quiet living room. Isla wrapped her legs around him and met every thrust.
“Harder,” she gasped. “Fuck your sister harder. I want to feel you for days.”
Theo grabbed her hips and slammed into her. “Listen to you. Filthy little slut begging for her brother’s cock. This is what you needed, isn’t it? Someone to use this greedy cunt the way it deserves.”
“Yes—use me—fill me up—”
He reached between them and rubbed her clit in tight circles. “Come on your brother’s dick. Soak me. Show me how much my sister loves getting fucked.”
Isla shattered with a muffled scream, walls clamping down. Theo fucked her through it, then pulled out, spun her around, bent her over the arm of the couch, and drove back in from behind.
“Ass up. That’s it. Take every fucking inch.” His hand cracked lightly across her ass. “This pussy is mine now. I’m gonna come so deep you’ll taste it. Gonna breed my own sister like the dirty girl she is.”
Isla pushed back against him, moaning. “Do it—come in me—fill your sister’s cunt—”
Theo’s rhythm turned brutal. He reached around and pinched her clit.
“Say it louder. Tell me what you want.”
“I want my brother’s come! Breed me, Theo—fuck a load into me—”
He slammed deep and came hard, pulsing thick ropes inside her. Isla moaned at the heat, clenching around him to keep every drop.
They stayed locked together, breathing hard. When he finally pulled out, white streaks slid down her thighs. Theo watched, then gathered the mess on his fingers and pushed it back inside her.
“Stay full of me. I want this cunt marked.”
Isla looked over her shoulder, eyes glassy. “Take me to my room and do it again.”
He carried her upstairs, still leaking, careful to keep quiet, and laid her on her bed. They didn’t sleep. Theo pushed back into her from behind, slow and deep, one hand around her throat just tight enough, the other playing with her tits while he whispered pure filth against her ear.
“I’ve wanted this since I was twenty. Wanted to walk into your room, pull your panties aside, and fuck you while you slept. Now I get to do it while you’re awake and begging. This pussy is never going back to normal. It’s going to stay stretched and full of brother-come.”
He fucked her through two more orgasms before filling her again.
Morning light found them still tangled. Isla woke to Theo’s mouth between her legs, tongue cleaning the mess he’d left, then two thick fingers pushing it back in. When she came on his tongue he climbed up and sank into her again, slow and deep.
“Morning, sis,” he murmured against her lips. “Still so wet for me. Still full of my come. I’m gonna keep you like this all day—naked, leaking, ready for your brother’s cock whenever I want it.”
Isla wrapped her legs around him. “Then stop talking and fuck me.”
He did—long, grinding strokes while he told her every filthy fantasy he’d ever had about her. How he’d watch her change when they were younger. How he’d steal her underwear. How he was going to keep her cunt permanently claimed.
They came together, quiet and intense.
The rest of the day was a blur of stolen moments while their parents were out.
He took her in the shower, her hands braced on the tiles, water streaming over them as he pounded into her from behind and talked filth the entire time.
“Feel that? That’s your little brother’s cock rearranging your guts. I’m gonna come so hard you’ll feel it in your stomach. Then I’m gonna make you push some out so I can watch it drip before I shove it back where it belongs.”
Isla came screaming his name into her arm. Theo followed, flooding her again.
Later he made her ride him on her bed, hands on her waist, watching her bounce with open hunger.
“Look at you. My perfect sister, riding her brother’s dick like she was born for it. These tits bouncing for me. This cunt taking every inch. You’re never fucking anyone else again. This body is mine.”
He flipped her onto her back, pinned her wrists, and fucked her harder, dirty talk never stopping.
“You’re my dirty little secret. My personal fucktoy. I’m gonna come home every night and bury myself in this sweet sister-cunt until you forget how to walk straight.”
Isla came so hard her vision blurred. Theo stayed buried and emptied another load deep inside her.
By evening her body was covered in marks—bruises on her hips, bite marks on her tits and neck, thighs sticky with dried come. She had lost count of the orgasms.
Theo lay beside her, two fingers lazily pumping in and out of her used pussy, keeping everything inside.
“I’m not stopping,” he said quietly. “Not after this. You’re stuck with your brother’s cock for the rest of your life.”
Isla turned her head and looked at him, eyes dark with the same hunger.
“Good. Because I’m not done being fucked by you.”
He smiled—slow, filthy, possessive—and rolled on top of her again.
This time it was slower, almost tender, but the words were still pure dirt.
“I love you,” he whispered as he sank deep. “I love my sister’s tight cunt. I love watching her fall apart on her brother’s cock. I love knowing no other man will ever touch what’s mine.”
Isla pulled him closer.
“Then keep it. Keep me. Fuck me until I can’t remember anyone else ever existed.”
He did.
For hours.
Until the only sounds left in the house were the wet rhythm of their bodies and the broken, filthy promises they kept whispering against each other’s mouths.
They were never going back.
And every night after belonged entirely to them.
Theo woke her again just after 2 a.m.
No words at first—just his mouth on her neck, his hand sliding between her legs, three fingers pushing into her still-slick, come-filled heat. Isla arched, already wet. He scissored his fingers, stretching her, then replaced them with his thick cock in one smooth thrust.
He fucked her on her side, one leg hooked high over his hip, slow and deep and relentless. Every time she got close he slowed down, keeping her trembling while he whispered pure filth.
“Not yet. You’re gonna stay right there, dripping around your brother’s cock, until I decide you can come. This cunt belongs to me. I own every orgasm that leaves it.”
Isla sobbed, trying to push back. He held her still.
“Beg for it. Beg your little brother to let you come.”
“Please—Theo—please let me come on your cock—”
“Dirtier.”
“Please let your sister’s dirty cunt come. I need it—I need another load of my brother’s come—”
He growled and finally gave it to her—hard thrusts and his fingers on her clit until she shattered. He followed right after, flooding her once more.
They barely slept.
Around four he carried her back downstairs for a few quiet minutes on the couch, laid her out, and ate her until she was shaking, his tongue cleaning every drop before pushing more back in with his fingers. Then he turned her over the arm of the couch and took her from behind, one hand fisted in her hair.
“You’re never leaving this house without my come inside you,” he snarled softly. “Every morning I’ll fill you. Every night I’ll top you up. This pussy stays claimed.”
When he came he stayed buried, grinding deep. Then he made her push some out so he could watch it drip, only to shove it back in with two thick fingers and a satisfied groan.
“Mine.”
Isla could only nod, wrecked and completely his.
Dawn found them back in her bed. Theo cleaned her gently, then pulled her against his chest, two fingers loosely inside her again.
Isla drifted off to the sound of his heartbeat.
She woke hours later to the feel of his mouth on her breast and his hand stroking between her legs.
Theo looked up, eyes dark and soft at the same time.
“Morning, sis.”
Isla smiled, sore and happy.
“Morning, brother.”
He kissed her thoroughly, tasting like sex and sleep. When he entered her again it was gentle, but the hunger never left. They moved together for a long time, dirty words still slipping between kisses.
“I love fucking my sister.”
“I love taking my brother’s cock.”
“This cunt was made for me.”
“Only you. Only ever you.”
When they came it was quiet, intense, and complete—eyes open, bodies locked.
Afterward they lay tangled in the sheets, weak sunlight spilling across the bed.
Theo traced the fresh marks on her throat and smiled against her skin.
“Same time tonight?”
Isla laughed softly, the sound rough.
“Good. Because I’m not done being your dirty little secret.”
He rolled her under him again.
And the day—and every day after—belonged entirely to them.