Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/ works/13445658. Rating: Explicit Archive Warning: Underage Category: M/M Fandom: おそ松さん_|_Osomatsu-san_(Anime) Relationship: Matsuno_Karamatsu/Matsuno_Osomatsu Character: Matsuno_Osomatsu, Matsuno_Karamatsu Additional Tags: Underage_Drinking, Drunk_Blow_Jobs, Face-Fucking Stats: Published: 2018-01-22 Words: 1857 ****** A Not So Bad Decision ****** by skittlematsu_(thewriterinpink) Summary The room they had chosen to do this in was abandoned, away from their family, the only light a flicker over their heads. It had illuminated Karamatsu's features in a way that made Osomatsu's stomach feel warm. Once he started getting a buzz in his system, one look at Karamatsu had set him on fire. It had really gone downhill after that. Karamatsu had been giggly and willing when drunk and took that clumsy kiss like he wanted it. Not once did that look cross his face, not like when it had when Osomatsu had suggested the alcohol. It had kept Osomatsu going. Notes Please enjoy this well deserved Osokara smut one-shot :) See the end of the work for more notes Sometimes when Osomatsu is drunk he makes bad decisions. He talks too much. He does stupid shit.   He gives his little brother head. That last one is new but he can't say he never thought about doing it before. Maybe sucking this particular brother's dick will make him less painful? Can anything make Karamatsu less painful? Ahhh, he is cute when he's drunk though.   The family is at a summer home right now. He's been spending a lot more time with his empty-headed brother during it. Osomatsu knows why, of course. Choromatsu's been annoyed with him a lot lately and Karamatsu always seems willing to spend time with anyone so he just gravitated toward him naturally. He doesn't think he'd be sucking Choromatsu's dick if he was here instead though, mostly because Karamatsu does something to his brain that makes him do even stupider things than usual. Must be all that empty air; it's contagious.   Drinking had been his idea. He had sneaked the drinks from behind his parents' backs and had coaxed his younger brother into sharing with him. Karamatsu had had that look on his face, the one that meant he wanted to say no but didn't want to disappoint dear onii-chan. Osomatsu had made sure to give him less because of that. The room they had chosen to do this in was abandoned, away from their family, the only light a flicker over their heads. It had illuminated Karamatsu's features in a way that made Osomatsu's stomach feel warm. Once he started getting a buzz in his system, one look at Karamatsu had set him on fire.   It had really gone downhill after that. Karamatsu had been giggly and willing when drunk and took that clumsy kiss like he wanted it. Not once did that look cross his face, not like when it had when Osomatsu had suggested the alcohol. It had kept Osomatsu going.   So now he is here, giving a clumsy blowjob to a boy he had helped his mom potty train. There had to be something a little wrong with that, right?   Karamatsu's breath is coming out soft and short, loud in the quiet of the room. He's warm under Osomatsu's touch, skin oddly soft; probably lotions daily like a weirdo. He smells nice too, like a summer's day. And home. And everything nice in this world. It's ridiculous how good he smells; like he appeals to every scent Osomatsu likes.   There's pre-cum on his tongue, but he doesn't dislike it. He sends his tongue hard over the tip of Karamatsu's cock and Karamatsu makes a small noticeable whine. It's the first sound other than breathing he's made and Osomatsu flicks his eyes up to him, grinning.   Karamatsu's cheeks are stained pink and his eyes are dark with lust, still twinkling under the hanging light like stars in the sky. His mouth is way too pink and his hair uncharacteristically messy. When their eyes meet, Karamatsu avoids his shyly.   Osomatsu pulls his mouth away and runs his hand that had been previously holding the base now up to the tip, caressing it with a thumb in a quick motion that can almost be considered skilled. He's sixteen; he at least knows how to jerk off.   Karamatsu looks at him then and Osomatsu wonders what he might be seeing. Probably a drunkard with a brother complex. Osomatsu knows he must look at least red-faced and horny because that's what he feels right now. A little bit in love too if he's honest, which he always is when he's drunk.   “Like what you see?” Osomatsu eventually asks. He can't keep silent for long and he wants to know the answer Karamatsu might give him. What do you say to your big brother giving you a blowjob?   Karamatsu's face flushes further. He looks a little tongue-tied but manages to push through like always. He's never one for staying quiet for long.   “Yes. I like it better when you have your mouth on me though.” He's honest about stuff like this when he thinks the one he's speaking to will like the answer, huh?   “Yeah?” Osomatsu asks, smirking. “It feels nice, right?”   He's just teasing. He can't help it, he's Karamatsu's big brother, it's what he does. Karamatsu goes scarlet; Osomatsu's mildly concerned he might not be able to finish Karamatsu off before he succumbs to fatigue.   Instead of waiting for an answer that might never come, Osomatsu begins jerking his little brother off slowly, watching Karamatsu's face as he does so. Osomatsu bites his lip because he's actually getting pleasure out of the fact he shouldn't be seeing this. Karamatsu's sexual expressions should be the farthest thing from his mind. How dirty. His masturbation sessions just got a lot more fun.   Speaking of masturbation, his cock feels neglected right now. It's not used to playing second fiddle to another. It'll have to wait for its turn. Karamatsu's cock gets first priority 'cause it's new and needy and Karamatsu's. Nothing can beat that.   “O-Osomatsu.”   “Hmmm?”   “M-More. Please?”   God, he's so adorable, he said please. Osomatsu is honestly shocked they're related. No way would he ever pull off a stunt like that.   Osomatsu is already picking up the pace. Karamatsu shivers this time, leaning into the touches and finally giving Osomatsu what he wants most: moans. Sweet, delicious, i-love-nii-san moans. Osomatsu shifts up to look at his brother better, tongue peeking out to wet his bottom lip. Karamatsu makes a lovely sight for Osomatsu's perverse imaginings. Osomatsu soaks it up before he goes back to what he knows Karamatsu wants from him. He can watch more some other time. If he gets away with this once, he'll get away with it again, surely.   He guides the cock back into his mouth, as far as he can take it. Osomatsu isn't surprised to find he doesn't have much of a gag reflex. In fact, most of it goes in easily and Karamatsu turns to jelly underneath him. Osomatsu bobs his head, gripping Karamatsu's hips tight with his fingers. Karamatsu becomes a mess of sound. Osomatsu wonders if anyone can hear it.   This is a lot stronger response than before. He knew Karamatsu wouldn't be quiet. He is too painful to be quiet.   Osomatsu doesn't hear any footsteps near them so he supposes they're good. He should probably be more worried of his parents catching him in this act with one of his brothers, but he's certain since they're on vacation and it's night time, they're probablybusy.   His other brothers are probably asleep. Hopefully, Karamatsu doesn't wake them.   Karamatsu's legs have woven themselves around his back, linking, and now he has no choice but to finish what he started, not that he was ever going to stop to begin with. Karamatsu uses this as leverage to jerk up though and that's a bit of a problem. It's throwing Osomatsu's rhythm off.   A part of him wants to let his brother have his way with him because that's hot. He can probably handle it too. Ahhhh, he's so hard. He might actually come by getting throat fucked at this point. He won't even be upset.   Ah, screw it, he'll let Karamatsu do what he wants. It's less work for him, right?   Osomatsu lets go of Karamatsu's hips and stops moving, loosening his jaw as much as he can. It takes Karamatsu a few moments to realize he's the only one doing anything, his rocking slowing down to nothing.   “Osomatsu?” He sounds confused and guilty, like he thinks he's done something wrong.   Osomatsu looks at him and winks. Karamatsu's brows furrow in confusions before understanding surfaces. Then he just looks concerned for Osomatsu's safety. And maybe a little bit excited.   “...Are you sure?”   Osomatsu gives him a thumbs up. Karamatsu's eyes glance at it and he nods, apprehension a bit on his face.   He doesn't say anything more. He picks up where he left off, this time doing all the work. It's a bit different now because Osomatsu has no idea of the pattern or a warning for when it'll change and that's exactly what he wanted. Karamatsu's noises get nice and sweet like music. He wants that on repeat. Maybe he can get Karamatsu to record them someday? Better yet, maybe he could film it and get the full experience?   There's no end to this rabbit hole once it starts, is there?   Osomatsu is shocked out of his thoughts about quickly descending brother complexes by a sharp thrust that hits the back of his throat and makes him see stars for a few seconds. Shit, he forgot that Karamatsu is actually kind of strong; that one almost hurt.   “Nnnn, O-Osomatsu, Aniki, I can't--”   What's he trying to say? Osomatsu watches his frantic expression. He seems to want something but Osomatsu isn't quick-witted enough to find out what.   Karamatsu whimpers pathetically and pulls away, untangling himself from Osomatsu and turning over onto his belly-- ah, that's what he wants. It's easier to thrust down than up.   “I'm sorry,” Karamatsu apologizes once he's on his hands and knees. He sounds like he's failed at something. Honestly, Karamatsu takes everything too seriously.   Osomatsu doesn't respond, just turns over onto his back and guides Karamatsu back into place. Karamatsu shakes in need the moment he's back in Osomatsu's mouth. Despite his apology, he doesn't hesitate this time. His thrusts are wilder and it occurs to Osomatsu he might be a little more inclined to move this time because he's close. No wonder he had sounded so desperate to change positions.   Hey, wait a minute, his hands are free now. He can jerk off as this happens. Osomatsu quickly unbuttons his jeans and dives in, moaning unabashedly when his hand wraps around himself. Karamatsu moans high in his throat in response.   Yeah, they're definitely going to finish each other off this way. He can safely say this is the craziest thing he's ever done under the influence. The best, but the craziest.   He thought Karamatsu was already making too much noise, but he's practically screaming by the end of it. Osomatsu's name too. He chalks his own orgasm up to that one, his luckily muffled under dick.   Satisfaction settles in his body. Cum tastes funny but he's swallowed that down with no trouble. Karamatsu slowly pulls off of him, turning and settling on his hunches. He looks peaceful, tired and still a little pink from beer. If Osomatsu squints, he might mistake his own baby brother for an angel.   Osomatsu moves toward Karamatsu and captures his lips again 'cause angels are meant to be kissed. Karamatsu sways into it, snuggling closer with lazy mouth movements. When Osomatsu pulls away, Karamatsu's eyelids are heavy. Osomatsu smiles, cupping Karamatsu's cheek and caressing his thumb against it. The heavy eyelids flutter.   “Nii-san...”   “Sleepy?”   “Mmhm.”   “Then let's get cleaned and go to bed then. If you want... we could make a bed here and cuddle. There are extra futons in the closet.”   Karamatsu smiles wide. He nods exuberantly. Osomatsu's never seen him so happy. It makes his heart flutter.   Maybe this wasn't a bad decision after all.   End Notes skittlematsu.tumblr.com Please drop_by_the_archive_and_comment to let the author know if you enjoyed their work!