My Sister: Forbidden Cumslut

Preface: I have never written a taboo story like this. TBH, I'm not sure how I feel about it, but fair warning, it's really filthy. Read at your own risk.

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My sister flops onto the picnic table opposite me with a huff. "You're not answering your phone. Was it really that bad?" There's laughter in her voice. Concern, too, though she masks it with an eye roll, taking a loud, obnoxious sip from her mocha latte.

"It wasn't that bad," I mumble, stealing her coffee out of her hands. It's too sweet. Sickly sweet, but I'm pissed at her, so I make an elaborate show of gulping half of it down. She steals it right back and grumbles.

"God, you're such a dick. No wonder they run screaming. Look, I don't know what you're doing to these poor girls, but I have no more friends to set you up with." She holds her hands out and shakes her head, like she's fed up with me.

I wave her off, ignoring the sting of embarrassment and shame, the reminder of why every girl I sleep with can't stand to look at me after. Fortunately for my sister, she's a queen bee in her tribe, and none of them will admit what went wrong on our dates to her face. I should probably feel bad they're likely gossiping behind her back about how her brother, older by two minutes, mind you, is a freak. But since that burden is mostly mine, I don't feel that bad for her.

"Stop trying to set me up with your friends, then," I argue back.

Reaching out to snag my hands, tugging them across the picnic table so the tabletop juts into my stomach, Chloe says, "I just want you to be happy, Sammy. You're always alone. You know we worry about you."

"You're not worried about me," I sigh, pulling my hands back. "You're worried about your reputation, that you share genes with your strange twin. Never mind I started my own IT firm at 18, make more money than both of our parents combined." I could go on, but the frustration is old. I'm independently wealthy, built my fortune up through my own merit, but our parents and my sister still think I'm weak. Pathetic.

I just like to keep to myself, not flaunt my wealth at parties like my parents and sister do. I'm shy. Quiet. That makes me less of a man in their eyes. And they don't even know about the other problem. The one that makes all her friends run away from me after sex.

I add, "Just stop trying to fix me up. It's not gonna happen. I'm destined to be alone."

"Sammy... what's really going on?" Chloe tilts her head, and I'm reminded of all the reasons I really do love my baby sister. We might be more different than two people could possibly be, especially ones that shared a womb, but at the end of the day, I love her bratty ass. She smiles warmly, and it lights up her face. The truth is, I'm jealous of Chloe. She's so beautiful. Everything comes so easily to her.

"Nothing's going on," I say, not wanting to burden her with my freakishness.

Chloe snorts. "Ok. So Amber, Kelly, and Erin all were psyched to be set up with my smart, hot, brooding brother. They lasted one date and now can't look me in the eye. Is it small? It's small, isn't it? You can tell me," she teases. Fuck, if my dick were small, she'd come off a righteous bitch right now.

"It's not fucking small," I snap, "and if it were, so what? It's all in how you use it. Besides, I've got a tongue, don't I?"

A blush creeps up Chloe's cheeks. We're teetering into inappropriate territory here. You're not supposed to talk about sex with your sister, even jokingly. But Chloe's brave, so she falters only for a second.

"Okay, so you're good with your tongue. And according to you, your dick is huge."

"Oh, for fuck's sake. I didn't say—" She's baiting me. It is pretty big, actually, but not the fucking point. But now I'm annoyed. Chloe, beautiful Chloe, skating through life. Fucked off in college, barely passed, and still our dad gave her a position in his company she's grossly under qualified for.

It makes me want to teach her a lesson by actually telling her the truth. I mean, it's not like I can feel any more ashamed than I did when I fucked her friend Amber and she stared at me in disgust afterward and I never heard from her again. Besides, if I can't trust my twin with my secret, who can I trust? So I straighten my back and admit, "I have a condition."

She perks up. "Oh? What kind of condition? Wait, are you okay?"

"I'm fine," I wave her off. "It's... It's called hyperspermia."

"What the fuck is that?"

"It means I cum a lot."

She doesn't say anything right away, but stiffens in her seat, staring intensely, eyes swimming with some emotion I can't name because I've never seen it on Chloe before. She doesn't break eye contact with me while downing the last of her coffee. "Define a lot." Her voice cracks, but that's the only indication I've affected her.

"Like... a lot. I don't know. Buckets, feels like."

Her eyes grow wider, pink dotting her cheeks. She sets down the empty cup and pushes her long blonde hair off her shoulders, then looks around the park. It's quiet, being in the middle of a workday, but there's a guy playing frisbee with his dog, and a woman running the bike path with a stroller. It's warm out. Sunny. All this normality makes me feel tense. I look back at Chloe, the sun catching her glowing tan skin.

She's wearing a low cut tank top, and while I might have, half-teasingly, said something about covering herself up, even just to piss her off, I can't bring myself to say the words.

Because it's hot out. But her nipples are hard through that tank top, and that I've noticed is worse than this conversation, even more problematic when I realize she knows I'm staring at her tits.

I clear my throat, ready for the shame, the verbal assault she no doubt has cocked and ready. My sister and I love each other, but get on our last nerves on the daily. We've been gold-star bickerers since we were kids. But Chloe surprises me.

"Maybe I can help."

"What?" Her casual, direct statement makes me shift in my seat. She must just be fucking with me. "No. No more dates, no more friends. I'm destined to be alone. Fuck it. Ugh, I can't believe I told you—"

"Calm down, spaz. No more dates, I promise. But... I don't know. I have an idea. You down?"

"With what, exactly?"

She grins mischievously. "It's a surprise." Then she comes to a stand, stretching tall, pushing her tits out, arms wide. I swallow the spit in my mouth and adjust in my seat, grateful I'm on the opposite side of the picnic bench and she can't see my budding erection. No doubt she'd tease me endlessly if she found out I sprouted a woody looking at her perfect tits. Fuck. I'm so fucked up.

"Meet me at my apartment tonight. Come over around six." Then she turns and walks away.

"Chloe!" I shout after her, but all she does is shake her ass in those tiny ripped blue jean shorts and wave me off. "I'm not walking in to any fucking surprises!"

I hear her laugh on the breeze.

I spend the rest of the afternoon stressed as fuck. While I might be concerned that my sister will tease me for my medical condition, and, if she bothered to notice, my inappropriate reaction to her fine as fuck body, I know she wouldn't tell anyone about it. Our bond is tight. Besides, both are out of my control. It's just my body's natural response, a biological reaction I have to deal with.

By six o'clock, I'm a mess. I've worked myself up into a frenzy, worried about whatever lengths she might take to so-called "help" me. My sister is in a class of her own. Bat shit crazy some days. Her ex-boyfriend threatened to put a restraining order on her for bashing his BMW with a baseball bat, but then begged her to take him back two weeks later. She's either a knockout in the sack or she drugged him. I'd believe it if both were true.

I'm late, and don't bother knocking when I let myself into her apartment. It's a loft with high ceilings, exposed beams, and floor-to-ceiling windows, on one of the top floors of a high-rise downtown. Rent is expensive as hell, but our parents and I, suckers that we are, pay for her lavish lifestyle.

"Okay, what's this plan?" I call out.

Chloe steps out of the bathroom wearing my old baseball tee and... nothing else.

All my annoyance evaporates. Her tits bounce as she walks closer, hard nipples pressing through the number 13. She swims in my shirt. It hits her mid-bare thigh, giving the illusion she's not wearing any underwear.

She walks toward me without saying a word, her knee-high socks leaving soundless steps across the hardwood floor.

I clear my throat and try again. "So. What's this grand plan of yours?" There. Totally unaffected. Just two siblings hanging out. Nothing wrong here.

Chloe reaches out and snatches my wrist, dragging me through her apartment. "You need to relax, brother. I love you, but you're so fucking uptight."

"I am not uptight."

"Please. That's half your problem. You probably freaked out after fucking my friends and you're the one that made it weird."

"I did not—"

"As far as I'm concerned, hyperspermia or whatever, is not that weird. I looked it up. So, we need to work on your confidence."

"Chloe, what—" But my words cut off when I realize we're standing in front of her bed. Chloe takes a step back. Then another, until the backs of her knees hit the mattress. And then—oh fuck, then her fingers curl around the bottom of my old baseball tee, and she lifts, pulling it off completely.

I stop breathing. I think my heart stops beating, too. I haven't seen my sister naked since... well, she didn't look like this. We were kids in the bathtub. Now, though?

Holy fuck, now she's perfect. Tan skin. Golden. Curves in all the right places. And I was right. Her tits are perfect. Her nipples, a dusky rose, are small and pointed. Hard. My mouth waters. I want to touch her. Oh fuck, I want to squeeze them. Suck on them.

"Sammy?" Chloe prompts. Her eyes are fire, but she's amused, too. Is this a game to her?

I don't realize I've said the words when she shakes her head. "You need to relax, big brother. Who better to help you get more confidence than the person who knows you better than anyone else in this world?"

"Chloe, I don't think—"

"Yes! Exactly. Don't think." And then she hooks her thumbs into her underwear, shimmies her hips, and drags the light pink material down her legs.

My cock strains against my pants. Jesus fucking Christ, what is happening right now? I should tell her how wrong this is. I should be halfway out the door.

But really, I just want to fuck her.

"Are you really ready for this? For me?" I ask. My voice comes out in more of a growl, surprising us both. I can't tear my eyes away from her pussy. Bare, the lips hiding what I'm sure, given the rest of her, is the prettiest, pinkest pussy to ever walk this earth. It makes me fucking feral. My dick strains so hard in my pants. I can feel the tip leaking.

Chloe nods, biting her lip and dragging a hand across her chest, pinching her nipple, before diving lower. I reach forward and snatch her wrist before she can touch herself.

"Is this really what you want, little sister? You want your big brother to fuck you?" I bend her arm and wrench it behind her, arching her back so her tits push toward me. Leaning down, I take a mouthful, tasting her expensive coconut body cream and something distinctively Chloe. She moans when I suck her nipple into my mouth, using my teeth to pinch the tip.

"Oh fuck, Sammy!" My childhood nickname on her lips has me smiling. But I'm not happy. I'm unhinged. Wild. I'm sucking on my sister's tits and it has me motherfucking savage with need.

"You fucking asked for it," I growl. Like she's unleashed a demon, I release her arm, then shove her onto the mattress. She lands with one bounce, then bends her knees seductively, still wearing nothing but those knee-high socks. I rip off my shirt and take off my pants, not bothering to make a show of it when my cock slaps up against my abdomen. I'm so hard I could break fucking glass with my cock, and I wonder, as Chloe takes me in, eyes wide with nerves, if she's having second thoughts.

But then she bites her lower lip and I'm on her in a flash, pushing her knees open, spreading those pretty pink lips. I was right again. The pinkest, sweetest pussy, glistening and ready for me, right there for the taking. "Are you wet for me, Chloe? Did you get wet for your big brother?"

I slap her clit with my hard cock, shaking it between us, and she moans, nodding her head.

"Thay's pretty fucked up, you know. Getting turned on by your brother." I push one finger, then two inside her. "You're dripping. Holy fuck, you're so wet for me. So ready."

"I am," she hums, eyes squeezed shut. I grip her chin and force her to look at me.

"Keep your eyes open, Chloe. You're not allowed to look away. You're going to watch your brother fill this filthy, needy cunt. Understand me?"

"Yes," she cries, but I grip her chin harder. "Yes!" She adds, more enthusiastically.

"That's more like it." And then I kneel between her legs, line up at her entrance, notch my cock and shove in.

Oh, holy hell, she's so tight. So fucking warm. Her pussy clamps down around me and we both grunt. I pull back out and push in, getting used to the feel of her. Of my sister. And her beautiful, perfect, pink cunt.

"Jesus, you're so fucking tight. How are you this tight? I know you've spread this pussy around town, how many men you have wagging their tongues chasing after you." I pull out, enjoying the drag, the tight vice grip of her cunt before pushing back in. "I know you didn't save yourself for your big brother."

"Maybe I—uh, oh, oh yes, just like that!" She rolls her hips, lifting her knees to her chest, and wraps her legs around me. It feels right. It feels like home.

It shouldn't, but it does.

I'm overwhelmed by how good this feels.

"Maybe what, Chloe?" My thrusts build faster. I'm slamming into her, her dripping wet pussy making squelching sounds, skin slapping, pressure building. Her pussy suckles me in and every thrust feels like a drug in my veins.

"Maybe I saved something else for you. Another first," she breathes, half-trying to keep up with me, half-shaking, lost in pleasure.

It takes me a second to understand what she means. And when the light goes on... "You're fucking in for it, Chloe," I threaten.

Pushing her knees into her chest, I roll her onto her stomach, pulling out only briefly, before shoving back in. Holding her ass high in the air, one arm wrapped around her torso, the other around her neck, I shove her face into the bedsheets.

Pulling out, I slam in, faster now, hitting her just right, and she screams. She's getting close, and her legs try to squeeze together, to chase the orgasm, but I won't let them, nudging my knees between hers so her legs are spread wide, ass cheeks jiggling.

I grunt when her hips shake in frantic need, pulling my orgasm too close to the surface. I'm not ready yet, so I slow down and slap her ass. "Behave!"

"Shh!" she hisses. "Mom and Dad might hear us! You need to keep it down!"

This fucking girl. "Maybe mom and dad should know what a fucking cumslut you are, huh? To know you heard one little thing about all my pent up cum, and your filthy cunt was gushing with need. Didn't they teach you better than that?"

"Oh god, Sammy! Mom and Dad will be so mad! You have to keep it down!" she screams into the pillow.

I laugh, then pull out. Palming her ass cheeks, nice and high in the air, I spread them, exposing her lovely, tiny asshole. The little ring, untouched, just for me. "Ok, lil' sis. I can be quiet. The question is, can you?"

Reaching between her legs, I slather my fingers in her soaking wet cunt, then push one, then a second, into her asshole, working them in to make some room. She tenses when I breach the barrier, but she lets me in.

Then, slowly at first, I work my cock into her ass, dipping in one inch at a time before pulling back out. In and out like this, so impossibly tight, her asshole squeezes me so hard I don't know how I don't come. "Relax, little sister. I'm your big brother. I'll always take care of you. You trust me?"

"I trust you."

"Good girl." And then I push all the way in. "Fuuuuck!" I grunt. She's trying to relax, but it's taking her a second to find her rhythm. Meanwhile, her tensity is choking my cock in the best way. "Play with your clit, sweet girl."

Her hand quickly disappears beneath her, and as soon as she starts masturbating, her ass relaxes. I pull out and push back in, and begin fucking her ass in a steadier rhythm. It's everything I didn't know I needed.

Pleasure snakes through my spine. My lower back tightens. Chloe shakes, her orgasm taking full control of her body, everything spasming all at once. I fuck her ass, harder, faster, pushing and pulling, feeling every sensitive nerve ending alight with pleasure while she bucks her hips back into me. Her ass cheeks jiggle, her hand working her clit furiously beneath her.

Her perfect asshole clamps around my cock, milking me, and I can't hold out any longer. I'm buried so deep, and she's spasming, vibrating like a fucking toy.

"You remember what I said, baby sis? About my cum? I know you're a cumslut, so you're gonna fucking love this. Get ready." And on the next thrust, I lose all control. My cock sprays deep in her ass, but that's just the start of it.

Pleasure zaps through me, long and wild, and I'm frantic, pounding into her, coming so fucking hard, erratic with my thrusts. Once, twice, thrust. Another shake. Thrust. I'm still coming.

I pull out, and Chloe lets out a loud, "Uhh!" I grip her knee and flip her over, still working my cock with my hand. Her eyes widen, and I keep pumping, shooting cum all over her stomach, her perfect tits. I rub it in with my other hand, aiming it up her neck, into her hair, on her face. Meanwhile, I'm just rubbing it in. I keep coming, my balls pulling up tight, my cock so sensitive I swear I'm almost empty, but still, I keep coming.

She's soaked. And I keep spraying, back down to her pussy, rubbing our cum together, then flatting my fingers and working her clit and until she's coming too, screaming, sobbing, grabbing the pillow and biting it to bury her cries.

Until it all slows down, and my whole body trembles. And we're panting. And filthy.

Not just cum filthy. We're brother-sister filthy.

My heart is racing. It's silent---a vacuum of heavy breathing and tension.

It's dark out now. The moon is out. The cityscape lights the sky through her tall windows. We're twenty stories in the air, but really, anybody could see in here.

Me and my sister. Filthy, cum drunk twins.

I look back down at Chloe. She's quiet. Subdued. More than I've ever seen her. I don't know what to do exactly, so I try to imagine this was any other time, or person, but it doesn't feel right.

I don't like the itchy feeling in my chest when I try to picture Chloe as anyone but my sister, which is all kinds of fucked up, but I'm not ready to unpack that yet. So I put my arms beneath her and pick her up bridal style and carry her to the bathroom. I set her down and turn on the shower. She says nothing while I lather up soap and start washing all the cum off her body. She lets me shampoo her hair, but swats my hands away when I try to condition it. I lather the soap again and clean myself off, and since she's still tending to her hair and I can't help myself, I clean her tits unnecessarily, feeling the nice warm, soft handful in each palm, thumbing over her still hard nipples. She doesn't tell me to stop, but gives me a shy smile.

We dry off, and I put on my underwear and pants. She slips my old baseball tee on again, but wears nothing else.

In the kitchen, I put bread in the toaster and dig out the strawberry jam.

Finally, after a few bites, Chloe snorts. "You really do cum like a garden hose." Then she gives me that fucking smile. The same one I grew up with, the snarky, annoying, bratty little sister smirk. I snatch the toast out of her hand and wipe the jam down her face.