Only Sis

© 2026 Igor Pajić

 

All rights reserved.

 

This book is a work of fiction. Any resemblance to real persons, living or dead, or actual events is purely coincidental.

 

The story contains explicit sexual content and is intended for mature audiences (18+ only).

 

No portion of this book may be reproduced, distributed, or transmitted in any form without the prior written consent of the author.

 

 

 

 

Only Sis

 

Kevin was eighteen years old and his life revolved around three things: school, video games, and porn. He was the classic nerd — tall and skinny, with glasses that constantly slid down his nose, messy hair that fell over his forehead, and T-shirts featuring prints from his favorite video games that he wore for days until they got so dirty he finally tossed them into the washing machine. He wasn’t ugly, just invisible. The girls at his school looked at him like he was part of the furniture — useful for copying homework, but nothing more.

 

Every evening followed the same ritual. After finishing his homework and spending hours grinding levels in whatever new game had captured his attention, Kevin would lock the door to his room, dim the lights, put on his headphones, and open his laptop. His browser history was an endless scroll of tabs filled with every category imaginable — solo girls, MILFs, roleplay, taboo… He jerked off almost every night, sometimes twice, chasing that quick release that helped him fall asleep. It was his only real outlet, his secret escape from a world where no girl had ever shown any real interest in him.

 

One particular night, the routine started like any other. He had just finished an intense session in his favorite RPG, his eyes burning from staring at the screen for so long. He leaned back in his gaming chair, stretched his arms, and opened a new private browsing window. His hand moved almost automatically as he typed in his usual porn site and started scrolling through the “recommended” section. The thumbnails flashed by — fake moans, perfect bodies, scripted pleasure.

 

Then something stopped him cold.

 

One of the preview images looked… familiar. Too familiar.

 

It was a close-up of a woman’s body from the neck down. Smooth, pale skin. Full, round breasts with soft pink nipples. A delicate silver chain with a small heart pendant resting between her cleavage. The way her fingers were teasing one nipple, the slight curve of her waist, the subtle birthmark just above her left hip… Kevin’s heart skipped a beat. He had seen that body before. Not in porn. In real life.

 

He clicked on the thumbnail before his brain could fully process what he was doing.

 

The page loaded. It was a premium amateur site — the kind where girls had their own profiles and fans paid monthly to watch private videos and live streams. The profile name was “RosieRoseX”. The banner image showed the same woman lying on a bed in lacy black lingerie, legs slightly spread, one hand between her thighs.

 

Kevin’s stomach dropped.

 

It was Rosie. His older sister.

 

Twenty-five-year-old Rosie — the confident, outgoing one whose bedroom was right next to his. They still lived together in the family home, their doors separated by only a thin wall. He could often hear her moving around, humming to herself, or talking on the phone late at night. Rosie who teased him endlessly about being a gamer nerd, who still stole his hoodies when she was cold, who smelled like vanilla and strawberries whenever she passed by him in the hallway. The same Rosie he had grown up with, fought with, and secretly admired for years.

 

But there she was, on the screen, completely naked in the preview video that started playing automatically. She was sitting on the edge of her bed — the very same bed that was just on the other side of the wall from his own — legs wide open, slowly rubbing her shaved pussy with two fingers while looking straight into the camera with that sultry, half-lidded expression he had never seen on her face before. Her voice — soft, breathy, nothing like the sisterly tone he knew — whispered, “Hi babies… Mommy’s so wet for you tonight…”

 

Kevin froze, his hand still hovering over the mouse. His cock, which had been half-hard from the usual scrolling, twitched violently in his shorts. A wave of shock, guilt, and something much darker flooded through him all at once.

 

He knew he should close the tab. He knew he should pretend he never saw it. But he couldn’t move. His eyes were glued to the screen as Rosie moaned softly, sliding one finger inside herself while her other hand pinched her nipple.

 

This was his sister.

 

And she was getting paid by strangers to play with herself like this — right here, in the house they shared, just a few feet away from where he was sitting right now.

 

Kevin’s breathing grew shallow. His mind raced with questions — how long had she been doing this? Did their parents know? How many guys had seen her like this? Had she ever done it while he was home? — but underneath all of that, a forbidden heat was already building in his groin, stronger and more intense than anything he had felt in a long time.

 

He swallowed hard, his throat dry.

 

His cursor hovered over the “Join for $19.99/month” button.

Kevin sat frozen in his gaming chair, the cursor still hovering over the bright “Join for $19.99/month” button. The preview video kept looping in the background — Rosie’s soft, breathy moans filling his headphones as she slowly fingered herself on camera. Every time her fingers disappeared inside her shaved pussy and came back glistening, his cock throbbed harder in his shorts.

 

His mind was a storm of conflicting thoughts.

 

This is wrong. She’s your sister. You’ve known her your whole life. You used to fight over the TV remote. She still calls you “little bro” and steals your snacks. You can’t do this.

 

But the other voice — darker, hungrier — was louder.

 

She’s right there. Just on the other side of that wall. She does this while you’re home. While you’re jerking off to random girls every night. Look at her… she’s so fucking wet. She likes it. She wants people to watch.

 

Kevin’s hand trembled slightly on the mouse. He had never once thought of Rosie in a sexual way before tonight. She was just his annoying, confident older sister. But now… now he couldn’t unsee it. The way her tits bounced gently when she moved. The little silver heart necklace swaying between them. The way her hips rolled as she rubbed her clit. The birthmark he recognized from years of seeing her in shorts and bikinis at family pool days — now framed between her spread thighs on a porn site.

 

He sat there for what felt like forever, breathing heavily, staring at the button. His cock was painfully hard now, pressing against the fabric of his boxers.

 

Finally, with a shaky breath and a rush of guilty excitement, Kevin clicked “Join”.

 

The payment screen popped up. He entered his card details quickly, heart racing, telling himself he could always cancel tomorrow. He just needed to see. Just this once.

 

The site loaded fully.

 

He was in.

 

RosieRoseX’s full profile opened in front of him. There were dozens of photos and videos. Teasers, full-length clips, live stream archives. Kevin’s eyes widened as he scrolled.

 

In one video she was on all fours, ass up to the camera, slowly pushing a thick pink dildo into her pussy while moaning loudly. In another she was riding a suction-cup toy attached to her headboard, her tits bouncing heavily as she rode it hard, whispering “Fuck me deeper, daddy…” In a third she was using a vibrator on her clit while two fingers pumped in and out of her, her face flushed and eyes glassy with pleasure.

 

Kevin couldn’t believe what he was seeing. His own sister — the girl who lived in the room right next to his — had an entire secret life as a cam girl and content creator. She owned a whole collection of toys: realistic dildos, vibrators, butt plugs, even a fucking machine in one of the longer videos.

 

His hand moved almost on its own. He pulled his shorts and boxers down just enough to free his aching cock. It sprang out, already leaking pre-cum at the tip. He wrapped his fingers around it and started stroking slowly, eyes locked on the screen.

 

For the first time in his life, he was jerking off to his sister.

 

The guilt hit him like a wave, but it only made his cock throb harder. He watched Rosie in a recent video — recorded just a few days ago, according to the date. She was lying on her bed (the same bed he could hear creaking sometimes through the wall), legs spread wide, using a large realistic dildo that looked almost too big for her. She was moaning louder than in the preview, pushing it deep inside herself, her free hand rubbing her clit in fast circles.

 

“Oh fuck… yes… fill me up…” she gasped on the recording.

 

Kevin stroked faster, his breathing ragged. He imagined it was him behind the camera. Imagined walking into her room right now and seeing this in person. The thought made him groan quietly.

 

He was so lost in the moment that he didn’t even notice how loud his own chair was creaking as he jerked off harder and harder.

 

On the screen, Rosie arched her back, her tits jiggling as she fucked herself faster with the toy.

 

Kevin felt his balls tightening. He was already close — closer than he usually got this quickly.

 

He kept stroking, eyes glued to his sister’s naked, writhing body, knowing full well that she was sleeping just a few feet away on the other side of the thin wall.

Kevin kept stroking faster and faster, his eyes glued to the screen where his older sister was fucking herself deep with the thick realistic dildo. Her moans were loud and raw in his headphones, her tits bouncing with every thrust, her face twisted in pure pleasure.

 

He had never been this turned on in his entire life.

 

His cock felt harder than steel, throbbing violently in his fist. Every stroke sent waves of forbidden pleasure through his body. The guilt was still there — screaming at him that this was his sister, the girl he had grown up with, the one sleeping just a few feet away behind a thin wall — but the arousal was so much stronger. It drowned everything else out.

 

He imagined walking into her room right now, catching her in the act, her eyes widening in shock as she saw him standing there with his cock out. The thought pushed him over the edge.

 

With a choked groan that he barely managed to keep quiet, Kevin came harder than he had ever cum in his life. Thick ropes of cum shot out of him, splattering across his stomach, his chest, and even hitting the bottom of his desk. His whole body shook, his legs trembling as the orgasm seemed to last forever. He kept stroking through it, milking every last drop while watching Rosie on the screen arch her back and cum at almost the same moment in her video.

 

When it finally ended, Kevin was left panting, covered in his own mess, staring at the frozen image of his sister’s satisfied face.

 

The guilt crashed over him like a tidal wave the second the pleasure faded.

 

What the fuck did I just do?

 

He quickly closed the laptop, wiped himself clean with some tissues, and threw them in the trash. His hands were still shaking. He changed into fresh boxers and crawled into bed, heart still racing.

 

Sleep didn’t come easy. Every time he closed his eyes he saw Rosie’s naked body, heard her breathy moans, remembered the way she called herself “Mommy” for her fans.

 

Then other thoughts started connecting in his head.

 

Why was her door always locked when she was home alone? Why did she get so annoyed whenever he tried to just walk into her room without knocking? Why did she always wait until the house was empty — him at school, parents at work — before doing anything suspicious?

 

It all made sense now. She was recording and streaming while the house was quiet. She had been doing this for who knows how long, right under their noses.

 

The next morning Kevin woke up feeling a strange mix of shame and nervous excitement. He went downstairs to the kitchen and found Rosie already there, sitting at the table eating cereal in her usual morning outfit — an oversized T-shirt and shorts that showed off her long legs. She looked completely normal. Just his big sister, humming softly to herself as she scrolled on her phone.

 

Kevin sat down across from her without saying a word. He couldn’t stop staring. Every time she moved, he remembered how those same breasts looked naked on camera. How those same lips moaned. How those same fingers had been inside her.

 

Rosie noticed. She glanced up at him a couple of times, raising an eyebrow.

 

“What?” she asked finally, her tone light but curious. “You’re being weird this morning. Did you stay up all night gaming again?”

 

Kevin didn’t answer. He just kept looking at her, his face slightly flushed.

 

She shrugged it off, but he could tell she sensed something was off.

 

When breakfast was over and he grabbed his backpack to head to school, a dangerous idea had already formed in his mind. He pulled out his phone on the way out the door, heart pounding.

 

He opened a new message to Rosie’s number.

 

He typed slowly, fingers trembling:

 

“I know your secret.”

 

He hit send.

 

Then he turned his phone to silent and walked to school, stomach twisting with fear and anticipation at the same time.

Kevin walked home from school with his heart pounding the entire way. The message he had sent Rosie that morning had been sitting like a live bomb in his pocket. He had checked his phone obsessively all day, but there had been no reply. The silence made him even more nervous.

 

When he finally reached the house, he noticed both parents’ cars were gone. They were still at work. The house was quiet — almost too quiet.

 

For a second he thought he might hear something coming from Rosie’s room. Maybe she was recording right now. Maybe he would catch the faint sound of her moans through the wall. But everything was completely silent.

 

He opened the front door, kicked off his shoes, and headed straight upstairs to his own room, still replaying in his head what he would say when he finally faced her.

 

The moment he pushed his bedroom door open, he froze.

 

Rosie was sitting on his bed.

 

She was wearing a simple tank top and shorts, her long legs crossed. His laptop was open on her lap, the screen clearly showing the RosieRoseX profile he had joined the night before. She had been scrolling through his browser history and the videos he had watched.

 

She looked up at him slowly, her expression a mix of anger, embarrassment, and something sharper.

 

“So…” she said, her voice low and tense. “What secret do you think you know, little brother?”

 

Kevin stood in the doorway, stunned. His mouth went dry. He had planned this moment in his head all day — how he would blackmail her, how he would take control — but actually seeing her here, in his room, holding his laptop, made his stomach twist with both fear and sudden arousal.

 

Rosie closed the laptop and set it aside. “How did you find out? And don’t lie to me.”

 

Kevin swallowed hard. His voice came out quieter than he wanted. “I… I found it by accident. I was just scrolling on a porn site and one of the thumbnails looked like you. I clicked… and it was you. I joined last night… just to see what you were actually doing.”

 

Rosie’s face flushed red. She looked furious, but there was also shame in her eyes. “You joined? You paid to watch me? You’ve been jerking off to your own sister?”

 

The way she said it made Kevin’s cock twitch in his pants. He tried to stay calm.

 

“I didn’t mean for it to happen like that,” he said. “It just… happened.”

 

Rosie stood up from the bed, crossing her arms over her chest. “What are we going to do now, Kevin? Are you going to tell Mom and Dad? Is that your plan? To ruin my life?”

 

Kevin took a shaky breath. This was the moment. His voice came out steadier than he expected.

 

“I won’t tell them… if you agree to my conditions.”

 

Rosie’s eyes narrowed. She looked at him suspiciously, clearly expecting the worst — that he would demand to touch her, to fuck her, or something even more twisted.

 

Instead, Kevin continued.

 

“I don’t want your money. I don’t want anything like that… at least not yet. I’ll keep quiet. I won’t say a word to Mom or Dad… if you let me watch you while you record in your room. Live. In person. Not just through a screen like all the other guys.”

 

Rosie stared at him for a long moment, completely speechless. The silence stretched between them. She clearly hadn’t expected that.

 

“You want to… watch me?” she asked slowly, her voice barely above a whisper. “While I’m… doing that? In my room? With my toys?”

 

Kevin nodded, his cheeks burning but his cock already starting to harden again at the thought. “Yes. I want to see it live. Not like the others who only see videos. I want to be there.”

 

Rosie turned away for a moment, running a hand through her hair. She was thinking hard. Kevin could see the fear in her eyes — if their parents found out, she would probably be kicked out of the house. They were strict. They would never understand.

 

After what felt like forever, she turned back to him.

 

“Just watching?” she asked, her voice tight. “You promise you’ll only watch? Nothing else?”

 

Kevin nodded quickly. “Only watch. I swear.”

 

Rosie bit her lower lip, clearly torn. Then, with a deep sigh, she finally spoke.

 

“Fine. I have to film a new video tonight anyway. You can… watch. But only this once for now. We’ll see after that.”

 

Kevin’s heart jumped. A rush of excitement flooded through him.

 

“Right now?” he asked.

 

Rosie looked at him for a long second, then nodded.

 

“Yeah… right now. Come on.”