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It's always like this.
Sweet little Itadori Yuji gets away with it all. Leaving with only a pat on the head, a kiss on the cheek. Always such a good boy. Mamma's favorite, mamma's perfect little prince. Birthday parties, sleepovers, unexpected gifts. He gets it all.
Sure, Sukuna could rationalize it with the fact that Yuji doesn't ever do anything necessarily all that bad but when Sukuna was Yuji's age, just a young boy, six years old—their mom was already using the belt as a form of punishment.
Maybe Sukuna just had a bad streak in him, always getting into mischief. Maybe it was worse than what other kids did at that age but Sukuna never thought so, especially not now that he has someone to compare it to.
Their age difference isn't all that great, just a few years but those few years seem to make a huge difference. He's not sure what happened between him and Yuji to make their mother flip like a buzzing light switch—especially because they get mistaken as twins most days. Their dusty rose hair and similar undercuts are unmistakable as familial.
Their mother's brutal words, harsh language and even harsher punishments with Sukuna get flipped to sweet songs and warm hugs when Yuji's boyish smile and plump cheeks make an appearance.
It's not fair. But Sukuna has learned that life just isn't that—fair.
Nothing he could ever do or has ever done would make up for all of the things their mom deems terrible. Shit, Yuji could take the exact same steps as Sukuna and she'd still crown him the prized prince.
He sits and watches as her soft touches and love radiate from her and into that young boy, wonders what it would be like to love that way, to be loved that way. He can't tear his eyes from it, it's like watching a car crash—devastating and painful but just as fascinating to witness.
And then there's Yuji, of course. Innocent little Itadori who follows Sukuna around like a lost puppy, trailing behind him day in and day out. It grinds his gears, it makes him snap, he loses his temper and in turn—their mother loses it on him.
He's only thirteen—freshly thirteen. He doesn't want Yuji following him and his friends around. It's embarrassing, honestly. It feels like Sukuna has no privacy and he doesn't want to be the child's constant babysitter. If their mom loves Yuji so much, why doesn't she just take him with her when she goes shopping or over to her friend's houses. Why is it Sukuna's job?
Yuji always wants to hold his hand, tug on the hem of Sukuna's shirt until it's stretched out. He's always too scared to go into the abandoned buildings his friends find and never mind inviting any girls along, there's no way he'd stand a chance with his baby brother hanging off of his arm.
When Yuji gets too tired, he climbs onto Sukuna's back where he falls asleep on the bike ride home or on the long walk around the neighborhood. He's not that heavy and Sukuna almost finds the weight comforting, bouncing against his back, his brothers small thighs placed firmly between his hands.
He tucks Yuji into bed, a warmth tugging at his chest for a fleeting moment before the resentment rolls back in at the sight of their mother coming in the front door and the accusations begin.
'Did you clean your and Itadori's room?'
'Did you keep him safe out there? You better not be lying to me, Ryomen.'
'Don't roll your eyes at me, boy.'
'Did you start on dinner?'
'Where is my sweet boy?'
It makes Sukuna's stomach churn.
Today is like any other.
Sukuna had gotten chewed out for leaving his drum-set askew in the driveway instead of putting it back in the garage the very second he was finished with it. He went inside to get a drink of water and found Yuji hammering incessantly on the cymbals, their mother rushing out to see what Sukuna was raising his voice about.
She wasn't only angry that he'd left them out for a moment too long but that Yuji could have 'hurt' himself climbing on top of them and that raising his voice at his younger brother wasn't helpful. Sukuna had earned himself a slap across the face.
He'd taken it unwavering, as he usually does. Placing the kit back inside the garage and deciding to go for a walk in the woods, away from the house, away from their mom and away from Yuji.
He thought about calling up his friends but at this point, he just wants to be alone. The mark is red and swelling across his cheek—something he doesn't feel like trying to explain off.
Before he could turn his back for the trail that leads into the dense forest from the backyard of their house, a small voice calls out to him. It's light and carries along the breeze, innocent and kind.
"Kuna! Mamma said I have to come with you!"
Fuck.
Of course, she did. How else would the world choose to torture and test his patience today? He stops in his tracks at the head of the dirt trail, his sneakers scuffing against rocks. He doesn't say a word, just waits for Yuji to catch up to him.
He feels the small hand curl around his oversized shirt hem. Sukuna lets out a long sigh before starting to walk again.
His strides are a little too large for Yuji's much smaller ones, who has to take double or triple the steps to keep up, his feet fumbling and tripping over rocks and sticks with underdeveloped coordination. Sukuna doesn't look down, tries his best to keep his vision forward in the treeline, headed to the destination in his mind.
"Kuna?" Yuji's small voice reaches his ears, almost too loud in the silence of the trees. The sun breaks through the cracks above, peaking through the branches and lighting the path. It's warm but not hot, just enough to dip your feet in the river and nap on a warm rock or wild grass.
"What?" Sukuna responds, not in the mood for conversation and especially not with the small boy still tugging a little too forcefully on his shirt.
"Are you mad at mommy?"
The question catches him off-guard. Why was Itadori thinking about that? They've been walking for at least twenty minutes, the house nowhere in sight, nor their mom. Is that what he's been wondering this entire walk?
He decides to be truthful. It's obvious to anyone with eyes that Sukuna and their mom don't get along. Surely, Yuji sees it too. "Yeah, something like that."
He can feel Yuji's hand tighten around his shirt, bunching it a little more, tugging it a little tighter around his neck. It'll be stretched out by the time they're back at the house, just like the rest of everything he owns. Marked by his younger brother.
"Are you—Are you gonna be mad at each other forever?" Yuji asks then, just as the rolling sound of the river makes it's presence known, breaking the surrounding silence.
"Maybe." Is all Sukuna can think to respond because he thinks—Yeah, probably.
He doesn't want to dwell on it anymore, it just keeps making him even more upset and he came out here to forget about their mom, to forget about the exchange they had before he left the house. He wants to act like that isn't real for a moment and just be.
He pries Yuji's hand from his shirt to which the boy protests, making a small whine in the back of his throat, his foot coming down in a stomp, his light up sneaker glowing blue and green.
Sukuna wanders forward to the water, slipping his shoes and socks off before he rolls the bottoms of his jeans to his knees. He steps in, letting the water cool him, dance around his feet and ankles. It's purifying.
He hears another whine from behind him and there stands Yuji, his small hands wringing tight in front of him. He wants to get in but he's nervous—he doesn't know how to swim, no one has ever taught him to.
Sukuna sighs once again, holding a hand out toward his baby brother. "Here. Come on, take your shoes and socks off." He urges him and Yuji nods, a smile growing on his face as he chucks his shoes and socks to the side and clasps his hand around one of Sukuna's fingers.
He steadies the boy into the water until they're standing side by side, Yuji's clothes become soaked almost immediately, the water coming up far higher than Sukuna thought it would. Yuji becomes comfortable and Sukuna decides to sit on the side, finding a spot of warm grass to dry his feet.
Watching Yuji play is nice—near peaceful. If it weren't for their mom, he'd probably like the kid. The way Yuji looks up at him time and time again to check that Sukuna is still there, still watching him. The way he calls out to Sukuna to have him watch some stupid attempt at a 'trick' which is really just him tossing a small stone or kicking up water onto the surrounding grass.
It's cute, kind of nice to feel wanted. Yuji does make him feel needed and it's in a way that no one else ever has. Sure, he's needed at home when their mother tells him to make dinner before she gets back or to put Yuji to sleep but it's not the same as this.
Not the same as when someone begs for your attention and when they don't receive it, they throw a fit. They feel such big emotions when they don't feel reciprocation from you.
Yuji has begun to shiver, the sun sitting a little lower in the sky as he comes climbing out of the river and over to Sukuna. His teeth chattering as the sheer clothes stick to his pale skin.
Shit, their mom is going to kill him if he brings Itadori home soaked with river water and chattering like he's been left out in the snow. He'll get worse than the belt, he probably won't get fed tonight or tomorrow and Yuji will be none-the-wiser.
"Fuck. Alright, take your clothes off." Sukuna commands at the young boy who stands there dumbfounded, his plump arms wrapped around his tiny chest as he continues to quiver. "Come on! Before you freeze to death." He reaches forward and Yuji's arms go up on instinct.
He strips his brother bare. No one else is out here, and no one else will be. It's practically private property and Sukuna hasn't seen a soul in these woods all the years of him playing out here.
Yuji obeys, lifting legs and arms as Sukuna drapes each piece of clothing over a warm rock to dry and taking his seat back on the grass. The second he's seated the boy comes running, tossing himself in Sukuna's lap, his face digging deep into his neck. He's searching for warmth.
Sukuna lets him, wrapping his arms around his little brother's body whose begun to squirm, rubbing his face back and forth, his bare bottom pressing against Sukuna's lap.
Thoughts of their mom cross Sukuna's mind again, he knows he's in for it when they get home, there's no way she won't be able to smell the scent of the river on Yuji's skin, the dirt caked on his striped shirt and shorts. It brings his blood to a boil with nothing to take it out on—
But Yuji.
He can't leave a mark, that would only end worse for him. A thought occurs to him, one he's had before but never acted on—several, really. Little images he's pushed away, stuffed deep into the dark crevices of his mind, only to be fed and stoked by their mother's own taunting and cruelty.
Sukuna shifts under his little brother, feels the press of his body against his groin. Yuji's warmth radiating through his jeans as he reaches between his brother's thighs.
Itadori's face is still stuffed in Sukuna's neck, his cold nose being warmed by his big brother's searing skin as his large hands wander, tan over pale. His skin is soft, smooth, peach fuzz and goosebumps. He takes a hand full of Yuji's inner thigh, baby fat not yet gone and Sukuna gives it a tight, painful squeeze that causes Yuji to yelp, his hand scrabbling for purchase on Sukuna's chest.
His hand clamps tight in Sukuna's shirt, a small fist, white knuckled. His face pulling back a bit from his big brother's neck as he lets out a soft sniffle. "Kuna?" It comes out wavering, questioning and high pitched.
"Shh—" Sukuna shushes him, won't pinch him again, doesn't want to leave a mark but wanted to relieve some of the built up anguish inside of him.
It wasn't enough.
He makes a rash decision, one he can come to terms with later when he's alone but for now his judgment is clouded with need and annoyance. He reaches underneath Yuji, pulling his half-hard cock from his jeans and pushes it in between his little brother's thighs.
He can see the head peaking through, two plump thighs on either side and Yuji's own small member resting in the middle. Sukuna huffs and Yuji lowers a small hand down, feeling at the odd protrusion, the weird sensation. His fingers tickle at Sukuna's head, he's throbbing now as Yuji's thighs squeeze him so tight—so perfect.
He'd used his hand plenty of times, thought about sticking himself in other things but this is unlike anything else—it's warm and soft—and alive. It smells like Yuji, smells like home and the odd-off feeling of wrongness only fuels him.
A drop of pre-cum spills from the tip and Yuji's small fingers rub against it, unsure of what it is or exactly what he's doing. He has no idea that it's riling Sukuna up beyond belief, that each stroke of his tiny fingers against his red tip is making this so much more pleasurable.
He can't take it much longer, moving his hands to hold Yuji's thighs together as he begins to rock his hips in time while bringing Yuji's little body forward and back to meet him. His small ass bouncing against his lap over and over again as he fucks between his little brother's thighs.
"K—Ku—Kuna?" Yuji asks. His head turning, leaning back against Sukuna's shoulder so he can look up at his older brother.
"S'alright, Yuji." Sukuna's breathing is heavy, he's panting, hips rocking into his brother's back as he feels the squishy warmth tense and release around him. It's fucking heavenly.
He feels his brother tuck his face back into his neck, hiding. He whines, sounding a little scared, a little nervous. "Mmmm—" It's the sound Yuji makes before he cries. Usually Sukuna would do anything for his brother not to throw a fit, their mother lurking around the corner to discipline Sukuna, blaming him but right now? He couldn't care less.
His hips continue to rock, skin brushing against skin, tight and welcoming as the heat builds in his groin. He can't help himself, can't stop himself as Yuji begins to cry. Sukuna can feel wet starting to pool in his neckline.
He reaches a hand up, hearing Yuji wail into the silent forest. "Kuna!" Sukuna wraps a hand around Yuji's mouth, feeling it open wide, nearly wanting to shove his finger inside to feel its warm-wetness but knowing it would be too much, he's getting carried away already.
Yuji squirms in his grasp, only making the sensation between his legs a little more slick with pre-cum, a little smoother, a little more angled.
"Shh—It's okay, Yuji. I'm—I'm just warming you up." Sukuna speaks, breathlessly into his baby brother's ear as he rocks into his thighs again and again. He feels Yuji nod his head and then there isn't much left in him.
One thrust, two and Sukuna has spilled hot and white between the boys legs, covering them completely with his sticky seed. Marking him.
His body feels hot from head to toe, tingling from top to bottom as he comes down from his high, releasing his brothers face as he pulls out from between his legs, tucking himself back inside of his jeans.
Yuji looks down at his legs and back up at Sukuna, a look of innocence, a look of confusion on his face.
Sukuna will have to rinse him off—defeating the purpose of warming him up, he supposes. He lifts Yuji and lowers him to the edge of the water, dipping his hand in like a cup and running it over the reddening thighs he had just been between, rubbing them completely clean of his spend before sitting back down at the edge of the water.
The clothes are likely dry but he still needs a few minutes to recoup, to think about what he'll do if Yuji decides to tell their mom about what he's just done.
Maybe he should just pack his things and run off. Just leave this place. They'd all be better off, anyway.
Yuji sits perfectly still in his lap until he feels those tiny arms slink around his neck, Yuji's body turning to face him, his little legs straddling a thigh. Sukuna looks down, watching as Yuji looks up, down, up again like he isn't sure he wants to make eye contact with Sukuna.
"Yuji?" Sukuna tries, unsure he wants the answer of whatever is going through the boys head.
He receives a whimper in response, his plump cheeks growing red as he hides his face once more in Sukuna's neck. Then he feels it, his little brother's hips start to move, small and tentative at first but it's there. Mimicking the way Sukuna had been just moments ago but this time, Yuji is rubbing himself against his big brother's thigh.
"Oh, Yuji." Sukuna sounds defeated but endeared to the boy at the same time. They're sharing something special now, something that will connect them—not just something Sukuna has done out of spite and his own selfish wants.
He grabs for his brothers hips, small and plush in his palms, guiding them down, pressing a little harder to help Yuji feel an adequate amount of friction. His tiny toes curl, his whimpers muffled in Sukuna's neck, timed with each grind against his thigh.
"Mm—Mm—Mm—" They're so light and sweet. Maybe their mother was right, the boy does do no wrong.
How could he ever be mad at him when he sounds this innocent and needy?
Yuji pulls back from Sukuna, his face red, his chubby cheeks streaked with tears and his small lips bitten. Sukuna can't help but watch, can't pull his eyes away when his little brother's face contorts, his eyes scrunching closed, his little fists gripping so tightly to Sukuna's shirt as his orgasm wracks his little body.
"Kuna—" Yuji whines his name like the air is punched from his lungs and Sukuna thinks he's hard again, achingly so.
"You're alright, baby boy. It's okay." Sukuna talks him through it as he comes back down, his eyes fluttering open, his entire body flushed and steaming hot in Sukuna's hands. The pet name falling from his lips like second nature.
Yuji's pupils are blown wide as he takes in his big brother's face, his body growing limp as exhaustion takes him over.
"Let's get you home." Sukuna states, cradling his precious brother in his arms as he picks his clothes up off the rocks, warmed and dry. He pulls them over Yuji, straightening them out and instead of forcing him to climb onto Sukuna's back, he decides to carry him.
The mess on his leg has begun to dry, their mom won't notice it anyway. She doesn't pay any attention to how Sukuna looks, how he dresses. He does his own laundry, she wouldn't dare touch it.
Yuji's head rests on his brother's shoulder, his legs wrapped around Sukuna's middle as his arms hold him securely, a fondness strong in his chest.
He gets it now—He thinks he understands what their mother is so obsessed with. Why she can't seem to leave Yuji alone, why she doesn't blame the young boy for a single thing. How could she? He means no harm, he just wants to be loved too. Sukuna can love him just like Yuji loves Sukuna.
They make it back to the house and to Sukuna's relief, their mother left a note on the fridge stating that she picked up an extra shift and she won't be home until morning. That he needs to feed them both and put Yuji to bed but that isn't anything new.
He doesn't bathe Yuji tonight, he'll wait for the morning, not wanting to wake the poor boy. Instead, he decides to tuck him into Sukuna's own bed. Sukuna's safe-place, the place where he knows that Yuji will be safe and within reach, this—this innate need to have his baby brother within his view pulls at him.
He finishes up the chores and showers himself, sliding into bed in just his briefs. Yuji must feel the warmth because he gravitates towards him almost immediately, his small arms outstretched and wrapping around Sukuna's neck as if this was something they've ever done before.
It's absolutely not.
Sukuna lets him, pulling him close to his chest, breathing in his sweet childlike scent.
"Mm—Kuna—" Yuji whispers, his eyes still closed, nuzzling deep into Sukuna's arms.
"I'm here, Yuji. I won't leave you. Not ever."