miyacest, shotacon, nsfw, dubcon / noncon established miyacest but one day atsumu’s magically deaged. osamu doesn’t know how old he is specifically, and atsumu’s being too much of a brat to tell him.

he seems to think it’s all so funny, and to be honest osamu can’t tell if atsumu’s mentally deaged as well or not. he quickly realizes he doesn’t care. atsumu’s being a brat and while he seems not to care about his own situation, he seems to /love/ tormenting osamu like this.

osamu can’t even say for sure what pushes him over the edge, or if it’s a culmination of his general frustrations and atsumu refusing to do the simplest tasks. because now osamu is in charge here, and while atsumu would brat at him at the best of times, it’s worse when there’s a

real power dynamic at play. because atsumu absolutely hates being told what to do by people who should be telling him what to do. osamu isn’t even really thinking when he drags atsumu’s tiny body over his lap. their ma spanked them when they were kids, maybe it’ll work now too.

he absolutely does not think about all the other times he’s spanked atsumu, because those were under very different circumstances. circumstances he shouldn’t be thinking about when atsumu’s become a kid again. atsumu squeals and pleads when osamu drags his little shorts down.

he squirms in osamu’s lap, but like this he’s so small he doesn’t make any headway even with only one hand holding him down. it gives osamu a rush he isn’t sure he should admit to. he spanks atsumu once, and atsumu screams, face red and puffy, tears welling up in his eyes.

osamu goes a little lighter on the next hit, but atsumu keeps crying, calling osamu a ‘meanie’. it makes osamu roll his eyes. atsumu keeps writhing in his lap with every spank, and osamu tries very hard not to acknowledge the heat pooling in his gut.

he can feel atsumu’s cock rubbing against his thigh, and he tries not to let his heavy breathing become apparent. it’s really not his fault—he’s been practically pavlovas into being horny when atsumu begs and cries. and despite this… situation, this is still atsumu.

the next spank that lands, his hand stays there, rubbing soothing circles into the red hot skin of his now little brother’s ass. atsumu stops begging, but the tears don’t stop, little huffs and snuffles coming from the shaking boy in osamu’s lap.

the message has been sent. he should stop. his thumb slips between atsumu’s cheeks, rubbing over the tight little hole he finds there. he’s sick in the head. he wonders if atsumu would care if he were in the right mental state. he wonders if he’d call him a freak.

he decides atsumu would think this is hot too. if osamu is sick, then atsumu is depraved. he pulls his hand back, offering his thumb to atsumu’s wobbling lips. his brother sucks on it eagerly. osamu is a sick sick man. maybe a dead one if atsumu remembers this later.

atsumu’s too small for them to get far. probably. maybe with time and effort… but osamu won’t go that far. he pulls his thumb from atsumu’s mouth with a wet ‘pop’, and he imagines the sound punctuates his descent to hell, that it’ll follow him all the way down.

he massages over atsumu’s pucker, watching his body tense and spasm with every movement. his little hands curl into the fabric of osamu’s pants. atsumu doesn’t say a word. osamu presses his thumb in carefully, slowly. steadily. atsumu moans. osamu is at peace with hell.

he holds atsumu down in his lap—not that his brother is trying to go anywhere. it’s awkward, using his thumb like this, but he makes do. he pulls atsumu’s cheeks apart to watch the movement, watching his finger disappear—in, in, in. atsumu’s breathing is stuttering.

osamu isn’t sure he’s breathing at all. it goes on like this for a while—too long maybe, but after a while atsumu started thrusting back against him, starting dragging his little cock against osamu’s thigh with more purpose whether conscious or not.

and when he comes—little face scrunched up so similarly to how adult atsumu’s does, the same noises as always but pitchier, younger—it seals osamu’s fate. his cock aches beneath atsumu. he wonders how far in he could get. he wonders how long it would take.

he keeps atsumu lying on his lap as he jerks himself off to the thought. he doesn’t know how long it’ll take to fix atsumu. he may as well use the time he’s got. fin.

i said i was having thoughts. :)