Cover of What Sis Knows

4 chapters · 13656 words · Read 0 times

Jonah is obsessed with porn, specifically anal porn, but he has not yet had a girlfriend or anyone to do anything with, despite turning 18. One day, he has a long and candid conversation with his older sister Kelly, who reveals tha she is not only very experienced in anal, she does it often. She shares a lot of things with him about her desire for it and how it feels. When she eventually suggest that she can show him what it's like to take a girl anally, it's just the beginning of a long anal adventure for the siblings, where they have sex in secret. All characters are over 18.

Chapter 1: The Awakening

The laptop screen cast its sickly blue glow across Jonah's face, painting shadows that danced across the walls like specters. His bedroom was a museum of secrets—posters of half-lit figures peeled at the corners, their paper edges curling like questions left unanswered. The air hung thick with the scent of stale coffee and something else, something electric and charged that seemed to hum beneath the surface of his skin.

His hand moved with practiced rhythm, muscle memory guiding him through familiar territory. The video played on—a woman's moans mixing with the whir of his laptop fan, the sounds bleeding together into a symphony that was both thrilling and hollow. Jonah's hazel eyes, earnest and wide, were fixed on the screen with an intensity that bordered on desperate. He watched the mechanics of it, the angles and positions, cataloging every detail like a student cramming for an exam he'd never be tested on.

The particular scene was his favorite. He'd bookmarked it weeks ago, returning to it with religious devotion. There was something about the way she arched, the way her partner gripped her hips, that made his chest tighten with longing. Not just for the act itself, but for the intimacy it promised. The closeness. The connection. He imagined himself in that scenario—not as a participant, but as someone worthy of being wanted.

A creak echoed from the hallway.

Jonah's hand froze mid-stroke. His heart slammed against his ribs as he fumbled for the mouse, clicking frantically to close the browser. The video stuttered, refusing to die. His fingers betrayed him, clumsy and shaking, as the unmistakable sound of footsteps grew closer.

Shit. Shit. Shit.

The browser finally closed, but the damage was done. His laptop's desktop appeared, pristine and accusing, as Kelly's knock came through the door. It was more of a courtesy knock—the kind that announced she was coming in whether he liked it or not.

"Jonah? You awake?"

He yanked his sweatpants up, nearly toppling off the bed in his haste. His cheeks burned with a heat that had nothing to do with embarrassment and everything to do with mortification. He ran a hand through his messy brown hair, hoping to God he looked presentable, or at least not like he'd just been—

The door swung open.

Kelly stepped in, and the room seemed to shrink around her. She was a presence, his sister—tall and striking, with the kind of figure that turned heads and stopped conversations. Her brown hair fell in waves past her shoulders, and her hazel eyes, so like his own, swept the room with casual assessment. She wore her off-duty clothes—tight jeans and a fitted top—and carried the easy confidence of someone who knew exactly who she was and what she wanted.

"Hey," she said, leaning against the doorframe. "You look like you've seen a ghost."

Jonah's voice came out strangled. "Just—just watching something. Didn't hear you."

"Mm." Kelly's lips curved into a knowing smile that made his stomach drop. "Right. That must be why you look like you're about to hyperventilate."

She walked in without invitation, her eyes roaming the room. The posters, the mess, the laptop still warm from use. She settled onto the edge of his bed, crossing her legs with an ease that felt almost dangerous.

"So," she said, drawing the word out. "How long have you been into the anal stuff?"

The blood drained from Jonah's face. "What?"

Kelly laughed. It wasn't mocking or cruel—just genuine amusement. "Relax. I'm a cop. I notice things." She nodded toward his laptop. "Also, you left your browser history open last time I borrowed your computer. The incognito tab doesn't hide everything."

Jonah wanted to die. He wanted the floor to open up and swallow him whole, to drag him down into the earth where no one would ever know what his sister had just seen. His mouth opened and closed, fish-like, producing no sound.

"Hey." Kelly's voice softened, and she leaned forward, her hazel eyes meeting his. "I'm not judging you. I'm the last person who'd judge anyone for what they're into."

"I—that's—" Jonah sputtered. "You weren't supposed to see that."

"Do you think I care?" She tilted her head, studying him. "I'm your sister. I've been changing your diapers since you were born. There's nothing you can do that'll shock me."

Jonah's heart hammered in his chest. The shame was there, hot and suffocating, but there was something else too. Something that flickered beneath the embarrassment like a spark catching dry grass. Kelly wasn't running out of the room screaming. She wasn't looking at him with disgust.

She was looking at him like she understood.

"I didn't mean to—" Jonah started.

"I know you didn't." Kelly reached out and squeezed his knee. The touch was warm, grounding. "And I'm not here to interrogate you. I just wanted to check on you. You've been locked in your room a lot lately. You seem... tense."

Tense. That was one word for it. Jonah felt like a pressure cooker about to blow, all those built-up fantasies and frustrations churning inside him with nowhere to go. He'd been living in his head for months, years, consuming content like it could fill the void where real intimacy should have been. But it never did. It only made the hollow ache worse.

"I'm fine," he said, but the words rang hollow even to his own ears.

Kelly's eyes narrowed, sharp and perceptive. "Bullshit. I know that look. I've seen it in the mirror." She paused, and something shifted in her expression—a calculation, a decision. "You're what, eighteen now? Legal. And I'm guessing you haven't... you know. Actually done anything."

Jonah's face went scarlet. "Kelly—"

"Don't be embarrassed." Her voice dropped, low and intimate. "It's natural. You've got all these desires and no outlet. You're a good-looking kid. I'm sure girls would be lining up if you gave them the chance."

"That's not—it's not that simple."

"Isn't it?" She studied him, her hazel eyes glinting with something he couldn't quite identify. "Girls sleep with guys for all kinds of reasons. Confidence. Chemistry. Curiosity. You just have to know how to read the signals."

Jonah swallowed hard. "And what if I'm not good at reading signals? What if I mess it up?"

Kelly smiled, and there was something almost predatory in the curve of her lips. "Then you find someone willing to teach you."

The words hung in the air, heavy with implication. Jonah's pulse thrummed in his throat. This conversation had veered somewhere unexpected, somewhere dangerous. He should have laughed it off, made a joke, changed the subject. But he couldn't. He was frozen, waiting to see what she'd say next.

"Anyway." Kelly stood, smoothing her jeans. "I'm going to grab a drink. You want one? We could talk more. About life. About... interests."

Jonah nodded, not trusting his voice.

Kelly paused at the door, looking back at him over her shoulder. Her hazel eyes held his, and for a moment, the air between them seemed to crackle.

"Don't worry so much, little brother. You'll figure it out." She winked. "And if you ever need help figuring it out, I'm more experienced than I look."

She left the room. The door clicked shut behind her, and Jonah collapsed back onto his bed, his chest heaving. The laptop screen glowed up at him, but he couldn't look at it. His mind was spinning, replaying her words again and again.

Find someone willing to teach you.

I'm more experienced than I look.

His sister was a cop. A police officer. She spent her days upholding the law, and yet—

Jonah pressed his palms against his eyes, willing his heart to stop racing. It didn't work. His mind kept drifting back to the way she'd looked at him, that knowing smile, that intensity in her gaze. It was probably nothing. She was just being a good sister, checking in on her baby brother.

But the thoughts lingered.

And when Kelly returned with two glasses of soda, settling next to him on the bed with casual intimacy, Jonah couldn't shake the feeling that something profound was about to change.

Kelly settled onto the bed beside him, the springs groaning under her weight. She handed him a glass, ice clinking against the sides, condensation already beading on the surface. The soda was cold, sharp, and did nothing to quench the dryness in his throat. He took a sip anyway, mostly to have something to do with his hands.

For a long moment, neither of them spoke. The only sound was the hum of his laptop fan and the distant thump of bass from the neighbor's apartment. Kelly stretched her legs out in front of her, crossing her ankles, and let out a contented sigh.

"So," she said, breaking the silence. "You want to talk about it?"

Jonah's grip tightened on the glass. "Talk about what?"

She gave him a look—the kind of look that said she could see right through him. "You know what. The stuff you watch. The stuff you think about." She shrugged. "You've got questions. I can see it written all over your face."

He opened his mouth to deny it, but the words died in his throat. She was right. He had so many questions, so many curiosities that had been building up for years, and no one to ask. His friends were just as clueless as he was. The internet was a maze of conflicting information and outright lies. And Kelly—Kelly was sitting right there, offering to talk, looking at him like she actually wanted to help.

"I just—" He paused, trying to find the right words. "I don't know how to explain it. I've been watching this stuff for years, but I've never actually... done anything. And I feel like I'm missing something. Like everyone else knows something I don't."

Kelly nodded slowly, her hazel eyes thoughtful. "That's totally normal. Everyone feels that way at first. The porn makes it look easy, but real sex is different. Messier. More complicated. But also better, if you're doing it right."

"How do you know if you're doing it right?"

She laughed. "Practice. Lots and lots of practice." She tilted her head, studying him. "You want to know what it actually feels like? The real thing, not the porn version?"

Jonah's pulse quickened. He nodded, not trusting his voice.

Kelly took a sip of her drink, settling deeper into his bed. Her posture shifted, becoming more casual, more intimate. She looked like she was about to share a secret.

"Well, first of all," she said, "the porn version isn't entirely wrong. The mechanics are there. But they miss the emotion, the connection. When you're with someone who actually wants to be with you, who's into it as much as you are, it's a whole different experience."

She paused, licking her lips. "For me, I've always been drawn to the more intense stuff. The things that push boundaries. I like anal a lot."

The words hung in the air, bold and unashamed. Jonah's throat went dry.

"Really?" he managed.

"Really." Kelly met his gaze, unflinching. "I know it's seen as taboo, but to me, it's just another way to feel pleasure. A deeper kind. When it's done right, when you're with someone who knows what they're doing, it can be more intense than anything else."

Jonah swallowed hard, his mind racing. There was so much he wanted to ask, so many questions he'd never dared to voice. And here she was, his sister, offering him answers without judgment.

"Does it hurt?" he asked, the words tumbling out before he could stop them.

Kelly's lips curved into a knowing smile. "It can, if you're not prepared. At this point, I've had so much of it that I hardly ever feel pain. What's left is this... fullness. This pressure. It feels like you're connected to that person in a way that goes beyond just physical."

She gestured with her glass, warming up to the subject. "I've been with guys who knew exactly what they were doing. They read your body, respond to every little twitch and moan. They know when to push and when to pull back. And when everything clicks, when you're both in sync, it's like nothing else in the world matters."

Jonah leaned forward, enraptured. "How did you know you were into it?"

"That's a good question." Kelly thought for a moment. "I think it started with a partner who was really into it. He was older, experienced. He introduced me to things I'd never tried before, including that. At first, I was hesitant. It felt taboo, forbidden. But he was patient, gentle. He made me feel safe. And once I discovered how much I enjoyed it, there was no going back."

"So you just... do it with anyone now?"

She laughed. "Not anyone. I'm picky. I like younger guys, actually."

Jonah blinked. "Younger?"

"Yeah." Kelly shrugged, casual as anything. "They're more enthusiastic. More willing to learn. And they don't come with all the baggage that older guys do." She smirked. "Plus, they tend to be more adventurous. Less set in their ways."

The implications of her words settled over Jonah like a warm blanket. He thought about all the times she'd brought guys home, the sounds he'd heard through the walls. He'd always assumed they were her age. But now, revisiting those memories with fresh eyes, he realized he didn't actually know.

"How do you meet them?" he asked, curiosity overriding his embarrassment.

Kelly's smile widened. "Lot of ways. Apps, mostly. There are sites specifically for people looking for casual hookups. You set your profile, list your preferences, and then you browse." She paused. "Sometimes I go to clubs too. Not the regular ones—the ones with private rooms in the back. Places where people go to explore without judgment."

Jonah's mind reeled. He'd read about places like that online, but he'd never actually known anyone who'd been to one. "What's it like? Being with a stranger like that?"

"Intense," Kelly said. "It's all about the body. No small talk, no expectations. You're both there for one reason, and that's to feel good. When you're with someone who's on the same page, it's liberating."

She shifted on the bed, turning to face him fully. The dim light from the laptop cast shadows across her features, making her look almost otherworldly.

"You know what the best part is?" she asked. "The moment right before. When you're both naked, and you can feel the heat coming off each other's skin. You look into their eyes and see that they want you just as badly as you want them. And you know that in a few minutes, you're going to be so deep inside them, or they're going to be inside you, and nothing else matters."

Jonah's breath caught in his throat. His mind conjured images he knew he shouldn't be having, images that made heat pool in his stomach and spread through his limbs. He shifted uncomfortably, trying to hide his reaction.

Kelly noticed. Her smile turned knowing, almost predatory. "You're eighteen, Jonah. Legal. You're not a kid anymore. You're allowed to want things. To feel things." She leaned in closer, lowering her voice. "If you had the chance to try it—all the things you've been watching—would you take it?"

He was frozen, caught between shame and desire. His mouth opened, but no words came out.

Kelly reached out and tucked a strand of hair behind her ear, a gesture so casual it seemed almost rehearsed. "I'm not trying to pressure you," she said. "I just think you deserve to know what's out there. What you're missing. You've been so locked up in your head, hiding away from the world. I hate seeing you like that."

"I don't know how to change it," Jonah admitted, his voice barely above a whisper.

"You don't have to figure it all out tonight." She squeezed his knee. "But know that I'm here. I can teach you things, show you how it works. If you want."

The offer hung in the air, electric with meaning. Jonah's heart pounded so hard he could feel it in his temples. She was offering him the answers to every question he'd ever had, the experience he'd been longing for, hidden in his room with only his laptop for company.

He looked at her—his sister, his protector—and saw a woman who wasn't judging him. A woman who understood exactly what he was feeling because she'd felt it herself. A woman who was reaching out to him across the divide of years and experience, offering to show him the way.

"Okay," he said, his voice shaky but certain. "I think... I want to learn."

Kelly's smile softened, and for a moment, she looked almost tender. "I know you do, baby brother. That's why I'm here."

Kelly's words hung in the air like a dare, and Jonah felt the weight of them pressing down on his chest. His heart hammered against his ribs as he watched her set her glass aside, the condensation leaving a wet ring on his nightstand. She was looking at him with those hazel eyes that mirrored his own, but there was something else in them now—a flicker of intent that made his skin prickle with anticipation.

"Before we start," she said, her voice dropping to something low and measured, "there's something you need to understand. The stuff you've been watching? It's not real. It's choreographed. Rehearsed. Two people performing for a camera. The real thing is messy and awkward and sometimes ridiculous. But it's also the most honest thing you'll ever do with another person."

Jonah nodded, not trusting his voice. Her hand was still resting on his knee, warm and grounding, and he found himself focusing on that point of contact like it was the only solid thing in the room.

"So here's what I'm thinking." Kelly leaned back slightly, crossing her arms under her chest in a way that made her biceps flex. "We start by taking some of the pressure off. You're wound up so tight you'd probably blow your load in five seconds if we jumped straight into anything."

Jonah's face went scarlet. "I—that's not—"

"Relax." She laughed, but it wasn't cruel. "It's normal. You've been pent up for years, feeding yourself a steady diet of porn that's designed to get you off in under three minutes. Of course you're going to be quick at first. The trick is learning how to pace yourself. How to build up the tension and ride it instead of just exploding."

She uncrossed her arms and reached for the hem of her shirt. "And the best way to start is to get comfortable with each other's bodies. To stop treating this like something shameful or secret and just... let it be what it is."

Jonah's throat went dry as he watched her lift the shirt over her head. The motion was unhurried, deliberate, and he found himself holding his breath as the fabric slid up her torso, revealing smooth skin and the outline of a black sports bra. Her stomach was flat and defined, the result of years of physical training, and there was a strength in her frame that he'd never really noticed before.

"You're staring," she said, a hint of amusement in her voice.

"Sorry, I—"

"Don't be sorry. Just look. This is the part where you get to see me as I actually am, not just as your big sister." She unclasped her bra with practiced ease, letting it fall away. "And I get to see you, too."

Jonah's mind went blank. She was beautiful—not in the airbrushed, manufactured way of the women on his screen, but in a real, visceral way that made his chest ache. Her breasts were full and natural, her nipples dark against her skin, and there was a confidence in the way she held herself that made him feel like he was the one being exposed.

"Your turn," she said, gesturing to his clothes.

His fingers fumbled with the hem of his t-shirt, the cotton clinging to his skin as he pulled it over his head. He was painfully aware of his own body—the narrow shoulders, the lack of muscle, the pale skin that had seen too little sun. Next to her, he felt like a child playing dress-up.

"Hey." Kelly reached out, tilting his chin up until their eyes met. "None of that. I'm not here to judge you, remember? I'm here to teach you."

She shifted off the bed, standing in front of him as she shimmied out of her jeans. The motion was fluid, almost casual, and Jonah's breath caught as she revealed the matching black underwear beneath. She hooked her thumbs into the waistband and pushed them down, letting them fall to the floor before stepping out of them.

For the first time in years, Jonah saw his sister naked. She was fit—impossibly fit, with the kind of muscle definition that came from rigorous physical training and disciplined habits. Her legs were long and strong, her hips curved with the subtle generosity of a woman who'd grown into her body with confidence. And between them, a patch of dark hair that made his heart stutter.

"Like what you see?" she asked, not teasing but genuinely curious.

Jonah nodded, words failing him.

Kelly smiled and knelt on the floor in front of him, her hands resting on his thighs. "Now, let's take care of that pressure. I'm going to help you get some relief, and then we'll talk about what comes next."

She worked his sweatpants down with methodical patience, her fingers brushing against his skin in a way that made him shiver. When she pulled his boxers down, his erection sprang free, achingly hard and already leaking at the tip. Kelly looked at it with clinical interest, her lips curving into a small smile.

"See?" she said. "This is what I'm talking about. You're so worked up you're already dripping."

Jonah wanted to cover himself, to hide his vulnerability behind his hands, but Kelly's grip on his thighs kept him in place. She leaned forward, her breath warm against his skin, and for a moment, she just looked at him. Then, without preamble, she took him into her mouth. All of him. She made a gulping sound as she swallowed him whole and began to blow his cock.

Jonah's entire body seized. The sensation was overwhelming—hot and wet and impossibly intimate. He'd imagined this moment a thousand times, watched it unfold on his screen in dozens of variations, but nothing had prepared him for the reality of it. Kelly's mouth was a revelation, her tongue moving in ways that made his vision blur.

She worked him with practiced skill, taking him deep before pulling back to tease the head. Her hands stroked the base, following the rhythm of her mouth, and Jonah found himself gripping the sheets as wave after wave of pleasure crashed through him. Her head moved up and down, up and down, and she made little grunting sounds in her throat, that was clearly out of pleasure. She LIKED sucking his cock! He could feel the pressure building, coiling low in his belly like a spring being wound tighter and tighter.

"K-Kelly—" he gasped. "I'm going to—"

She didn't pull away. Instead, she doubled down, her pace quickening as she took him to the root. Jonah's hips bucked involuntarily, and he came with a strangled cry, his release pouring down her throat. Hot jizz spurted from the head and against her tongue and palete, he watched her swallow several times, one hand gripping his hip as she milked every last drop, and when she finally pulled back, her lips were slick and her eyes were bright.

"See?" she said, her voice slightly hoarse. "That wasn't so bad."

Jonah collapsed against the bed, chest heaving, every nerve in his body firing with phantom sensation. His mind was a fog of pleasure and disorientation, the lines between fantasy and reality blurring into something he couldn't quite grasp.

Kelly stood, stretching her arms above her head with a satisfied sigh. She looked down at him with that knowing smile, and Jonah felt a shiver run through him that had nothing to do with cold.

"There," she said, settling onto the bed beside him. "Now that we've taken the edge off, we can really get to it."

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