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His phone buzzes with a text from Yuuji, which Sukuna ignores at first, tasting bitterness on his tongue while he frowns at the screen. What does his sister want when she ditched him for her girlfriend?
He opens the chat with a grumble after a while, unable to ignore her for too long. It makes his blood boil, the way his twins' name won't leave his head once he starts thinking about her. Even when she isn't in the house, Yuuji never leaves Sukuna.
It's a video, with no more text like the usual rambles or stupid string of emoticons Yuuji’s so fond of using when she sends Sukuna some random videos. Just a black square this time, there's nothing on the preview, so he has to click play to watch whatever Yuuji just sent him.
He recognizes those strands of pink hair in the shot immediately, sees them everyday, in the mirror, in every fantasy Sukuna has had about exactly what Yuuji’s doing in the video. In them, he tangles his fingers between them, feeling how silky they are, pulling them gently and making Yuuji whine like the spoiled little shit she is, but Yuuji only sounds like that in Sukuna's fantasies. Her voice is lower in the video, desperate. She's not whining, she's begging, and the hands pushing her to suck cock like a whore aren't Sukuna's.
Yuuji’s head bobs along with the movements of tanned hands, big hands holding her back from choking like an amateur, too eager, clumsy; gently guiding her to take the massive cock into her mouth slowly, as if she's being taught. Sukuna can't make himself stop looking, anger sizzling under his skin with each second he watches. Awe mixing along as he admires the way Yuuji stuffs her face full, no gag reflex. It's exactly how he has pictured it -his twin a natural at taking cock-, except it isn’t him in the video.
"That's a good girl." A low voice grumbles, condescending and filled with arousal. A growl teetering on the edge of danger.
"You're gonna hurt her." A softer voice says, and Sukuna tenses up. He recognizes it instantly, and he fucking hates who it belongs too. He has had to hear Yuuji’s girlfriend talk longer than he would have liked to, since they moved to Tokyo months ago. Every tone that Megumi uses to snarl at him to fuck off, and the way it changes when she calls Yuuji's name, an airy timbre to it, like she's breathing his sister’s name in. Filling her lungs with it. It's disgusting, but the thing Sukuna hates more, it's the way it makes Yuuji smile.
"Then come help her, sweetheart." The man says, pulling Yuuji’s hair gently, his cock leaving her mouth with a wet pop . Sukuna can’t place it, but he thinks he has heard it before. Maybe some fucker from school, someone he knows too.
Megumi grumbles and there's movement from the camera angle, panning the shot open as Megumi kneels besides Yuuji and glares at the camera. Deep green eyes boring into Sukuna’s like she knows he's there, watching. The same hatred reflected in her eyes.
Yuuji’s face finally comes into the shot then, and Sukuna's hips almost buck on its own. She has only been at it for a short while but she looks ruined already, lips swollen and cherry red, coated in spit and precum. Her eyes are twice as wide as usual and she’s teary eyed. She looks so pleased and content, Sukuna grips the phone until his knuckles turn white before he can throw it across the room.
Megumi cradles Yuuji's face, licks her lips clean and the drool running down her chin before kissing her, deep and slow, like she's tasting every corner of Yuuji’s mouth, chasing the taste.
The man jerks himself off while Yuuji and Megumi kiss, sucking on each other's tongues. When they finally separate, Yuuji smiles at her girlfriend like Sukuna has seen her do when they’re kissing at school, soft and endearing. It makes Sukuna grit his teeth.
"C'mon, don't make daddy wait." The other breaks their little moment, and Megumi glares at the man who’s talking out of frame. "Put your pretty mouths to better use."
"Don't be gross, dad." Megumi grumbles.
Dad.
Sukuna stays frozen, staring at what’s happening on the screen, his brain zoning out from what he's watching while he understands who is in the video with Yuuji and her girlfriend. Megumi's dad. Fushiguro Toji.
Anger rises up in his throat until it chokes him with nausea. Bile has never tasted worse on his tongue.
He has seen the man once or twice, just recently, one time Yuuji went to Megumi house in his car from school, another at a bar. He remembers having to do a double take for the first time in his life, roaming the man’s broad frame from head to toe. Each imposing muscle and raw confidence in every movement. The hard stare he fixed Sukuna with over Yuuji’s head, and the vicious smile.
"Fuck." Toji groans, and Sukuna focuses back on the screen, the images of Yuuji and Megumi slurping around his cock, kissing and sucking each other's faces while they pleasure the man. Megumi’s dad.
Sukuna laughs, staring at Yuuji’s flushed face. His pretty sister. A fucking liar.
He’s rock hard in his pants, and he hates it. Envy is not a feeling Sukuna feels often, but he feels it consume him now. Humiliation angering him further when he understands it wasn't Yuuji who sent the video. It was Toji.
Toji knows. Why Sukuna’s eyes never leave Yuuji, why he hates his daughter so much, why Megumi hates him back. Maybe she told him, or Yuuji, maybe he just knew it from that one time he saw him and Yuuji together. Sukuna knows he's not being subtle, he doesn't care to be. Maybe everyone knows, like Yuuji fears so much. That Sukuna wants to fuck his own twin. That she's his.
He keeps on watching the video, studying every expresion Yuuji makes. The hunger and reverence she’s almost worshiping him with. Sukuna's own erection throbs in his pants but he refuses to jerk himself off. Not to this.
He watches as Megumi and his twin make Toji come, moaning like it's them the ones being pleasured when he splatters his cum all over their faces, and Sukuna seethes with the need to lick her sister's face clean, instead of being grossed out. She's beautiful like that. A perfect slut.
"Smile, baby girl." Toji coos, kissing Yuuji on the lips, and the video ends there.
Anger and arousal drum in Sukuna's veins, his whole body strung up. He plays it again, watches each interaction closely, and studies Yuuji’s face. Listens to Megumi call him dad again and again. Burns the images in his brain.
He barely registers how much time passes while he stares into the black screen of his phone. Waiting for Yuuji to come home. He hates playing into someone else's game, but like hell he's not going to make Yuuji pay for it.
When he hears the front door open, he bolts out of his room, seeing red.
"You're a fucking hypocrite." Sukuna spits as soon as he sees his twin. Yuuji flinches away, frozen on the door mat while staring at Sukuna with confusion written all over her face.
"Wh-what?"
"You're fucking Megumi's dad, aren't you?" Sukuna tells her, and the way her face twists from surprise to utter horror amuses him. He doesn't need any more confirmation than what he already saw, but he wants to hear her admit it.
"What? A-are you insane?" Yuuji stutters.
"Don't fucking lie to me." He snears.
"I’m not lying." Yuuji scrambles to Sukuna in shaking legs. "What are you talking about?"
Sukuna laughs, a bitter sound that makes his throat burn. The closer Yuuji is, the angrier he gets. He can see the way she's still flushed, the bite marks and hickeys he thought were only from one possessive asshole, her swollen lips, the strain in her step.
"Thought I wouldn't find out?" He shoves his phone on Yuuji’s face, halting her where she is as the video starts playing. Sukuna watches her face closely, heat rushing to her cheeks. She looks almost ashamed, mostly horrorized.
"How did you-? When-?" Yuuji trails, staring at Sukuna's phone with eyes filling with tears.
He chuckles. "What? You didn't know about it? Weren't you putting on a show for me so I'll know you've been fucking your girlfriends' dad?"
"Toji-san..." Yuuji whispers, looking up at Sukuna.
"Toji-san, Sukuna mocks, sent me this."
Yuuji gapes, incredulity and hurt written all over her face, like Sukuna just broke her favorite toy, a common occurrence from when they were kids. He has the impulse to bully her into forgiving him with forceful kisses and some skinship, but they're not kids anymore, and Sukuna is not the one who was to repent this time.
He stalks towards her. "You told me it was wrong, that I was wrong." Sukuna snarls. His nostrils flaring with anger. "Fuck, you were such a bitch about it, but you've been whoring yourself to Megumi’s dad? While she fucks him too?"
Sukuna watches Yuuji’s breath stall, her throat closing as tears start spilling down her face. He has always been rough with her, forceful, possessive, sometimes scary. Sharp edges around his brotherly affection, but he had never been cruel.
"Kuna..." She whispers, her hand coming up like she wants to reach for him, but Sukuna slaps it away, glaring back and watching her heart crack.
"Don't fucking call me that." He spits.
"It isn't like that, Kuna! Listen, I didn't mean-" She tries again, but Sukuna holds her wrist in a bruising grip.
"You didn't mean what?" He pushes, walking her back against the wall, crowding her space. "You didn't mean to fuck him? Please, you're not stupid. He doesn't gross you out because he's not related to you?"
"You don't gross me out." Yuuji’s voice fills with desperation.
"How can you still date her when she's fucking her dad? You told me I was sick!" Sukuna snaps. Pressing himself against Yuuji. His body's shaking, overbearing and oppressive, when he traps her against the wall and himself.
"I didn't say that!" She sobs.
"You didn't have to."
Yuuji looks him in the eye, hers red and overflowing with tears when she sees the disappointment directed at her.
"They aren't different from me. Your own brother that disgusts you so much." Sukuna says through gritted teeth, his voice lower now that he's so close to Yuuji, whispering, his breath an inch away from her trembling lips. "But you love her more than you love me."
"No. No, I don't! Is not like that." Yuuji sobs back, cradling Sukuna's face in her hands.
"Liar." Sukuna accuses.
"Sukuna, please! How could I love you less?" She begs.
She has always worn her heart on her sleeve and Sukuna can see the damage being done. Is why he knows he can push her like this, make her finally admit she wants him too. Use all that bullshit of being each other’s half and twin souls Yuuji likes so much, against her.
"Let me fuck you then." He says.
Yuuji stares back, uncertain, but her eyes aren't scared like the last time Sukuna asked the same thing. When he told her about who he masturbated to, what he wanted to do to her, when she shook like a leaf under him before pushing him away and storming out of the house. She's considering it this time. She doesn’t have to pretend anymore.
"Prove you love me too."
Yuuji swallows and nods, barely a movement of her head, but is enough for Sukuna to finally devour her lips like he's been wanting to. She tastes sweet, like toothpaste and artificial cherry.
Her lips are swollen and soft, plush when he licks them and pries them open. Yuuji lets him, starts relaxing under him as she holds onto his shoulders. He wants to map every part of his twin, know why she drives him insane with need. She tastes addicting, tastes like everything Sukuna has wanted.
"Did you come right after fucking them so I could smell it on you?” Sukuna asks against her neck “You're still dripping wet with his cum? You smell like her." He noses her throat and sucks a hickey there of his own. His mark over the others.
Yuuji doesn't answer, her breath quickens and she gasps when Sukuna's hands slide under her skirt, kneading and caressing her naked thighs. Pressing his neglected erection and grinding against her.
"Kuna." She breathes, pushing her hips back, finding a rhythm along him. Arousal spills from her, as fiery as Sukuna's, and he wants her even more now, willing and shameless like this.
He pries Yuuji’s legs open and presses his palm against her crotch, feels her damp and hot, the fabric of her panties sticking to her pussy.
Anger and arousal pool low in his gut. He hates sharing. Despises the idea of someone else taking what is his, but the way Yuuji is right now, how much of a slut she has become, ready and hungry for more. Sukuna is gonna enjoy it.
He grabs Yuuji’s thigh and makes her wrap her leg around his waist while he pushes her panties aside. Watches her moan loud and clear, throwing her head back, when he coats his fingers in the mess dripping from her and rubs her clit, making her wetter for him.
When he pushes his fingers in, they both groan. She's so hot and dripping, messed up from the inside as Sukuna's fingers feel around her velvety walls. She doesn’t need him to finger her, she's open and ready, used, but Sukuna won't miss his chance, can't miss feeling her in every possible way, finally, even if his cock throbs painfully inside his jeans, bursting with need to bury himself inside her, claim her already.
"Tell me you want this. You want me." He demands, boring into her eyes, watching the twin flames reflect in her brown eyes the way they burn in his crimson ones, the only feature on their faces that has always differentiated them.
"Su-Sukuna." She moans, canting her hips to meet his fingers, taking what she wants from him.
"Say it. That is me, just me." He hurries her, his fingers massaging her sweet spot, making her legs tremble.
"Fuck! Sukuna, please. I want you, please!"
Is not what he wants. He knows Yuuji won't say it. She will keep dating Megumi, and fucking her dad too, no matter what will happen between them. He can see it in the way she craves more, has grown addicted to the feeling between her thighs, the hunger in her eyes. The worst part is that it makes Sukuna grow even harder, knowing his sister won't give it to him so easily.
"I'm gonna ruin you." He threatens, unzipping his pants and wrapping a hand around himself to guide his cock to Yuuji’s cunt, coating it with her slick.
She takes him so easily, opening up around him and tightening with each inch Sukuna pushes inside her, keeping him close.
"Fuck." He groans.
Yuuji’s perfect around him, tight and hot. He has to grit his teeth so he won't cum like a moron just after sheathing himself to the hilt. She’s panting against his neck, nuzzling her face on his shoulder. Sukuna wants to hear for himself the way she sounded in that video. High on pleasure, begging for more.
He thrusts hard, making sure Yuuji will feel him no matter how good Toji fucked her. That she'll remember him. She whines, needy, and a shiver runs down Sukuna's spine. He drinks the sound straight from the source as he kisses his twin and fucks her right there against the wall.
Yuuji sobs his name brokenly, tries to meet his pace, as desperate as he is.
"Ah, more, Sukuna, more...!" Yuuji begs, clinging to him like she never wants to let go, squirming when he nibbles on her ear, tongue swiping behind the shell.
"Come for me, Yuuji. Come for your brother. I'll give you just what you want." Sukuna says, his thrusts deep and hard, feeling Yuuji clench up and come around him, shaking in his embrace.
He follows right after, Yuuji’s walls milking him for it. Their moans entangling with each other as Sukuna fills his twin full with his cum.
" Mine ." He whispers, expecting a reassurance that Yuuji doesn't give. Instead, she presses soft kisses across his face, her eyes apologetic. It's infuriating.
"I love you, Kuna." She says back, a soft gasp following when Sukuna pulls out of her.
"I know." Sukuna says, smiling when he shows Yuuji his phone and presses send on the video he just recorded for Megumi. "Let's see how your girlfriend likes it."