Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/ works/9789356. Rating: Explicit Archive Warning: Underage Category: M/M Fandom: おそ松さん_|_Osomatsu-san_(Anime) Relationship: Matsuno_Karamatsu/Matsuno_Todomatsu Character: Matsuno_Todomatsu, Matsuno_Karamatsu Additional Tags: Blow_Jobs, Underage_Sex, Age_Difference, Sibling_Incest, Car_Sex, Coercion, maybe..., One_Shot Stats: Published: 2017-02-16 Words: 2589 ****** Kara-touto & Totty-niichan ****** by PeteyPiranha Summary i'm sorry mom the tags are your warnings. be prepared. Notes See the end of the work for notes Karamatsu's last class of the day is gym class, and Todomatsu is the one to go get him. He's still in his tight little gym uniform that barely covers him up. Todomatsu picks him up from school, and his little brother hasn't gotten a chance to change. His uniform is a size too small. He was the last one to get it because he was sick the day they handed them out. Todomatsu can see the lines of his cute white underwear underneath. The small shorts ride up his butt, and Karamatsu keeps having to sneak a finger in the bottom hem to stop it from going up too far. He doesn't know any better, he's too small and naive. Todomatsu's at the front of the building; he just got off work and is scanning the area desperately for his tiny little brother. Once he sees him he doesn't tear his eyes away for a second. There's dirty old men around here, ones that wouldn't treat his little brother with the proper care he deserves. He makes a straight line directly towards Karamatsu, weaving between the other small children. When he reaches him, he walks with his hand on his little brother's back, leading him. He won't let anyone look at his little sibling the wrong way. Karamatsu belongs to him, he's his. He lets his fingers wander a little too low; it makes little Karamatsu feel safe. He's got a bandaid on his knee, and when they get to the car the older asks him what happened. "O-oh i just scraped it.. is all..." Karamatsu replies sheepishly, obviously lying. "Did the older kids push you down again?" Todomatsu presses, trying not to let the protective anger seep into his voice as he backs the car out of it's space. His little brother doesn't respond, but picks at his fingers instead. "Kara- touto~," the elder coos at him. Still no response. "Why don't you tell me about your day while i drive us to go get a treat, hm?" That elicits a reaction from the little one as Todomatsu smiles into the rear view mirror at him. He pipes up and launches into everything he did at school that day, while his older brother drives them to an ice cream shop. After a short drive and a not so short explanation of Karamatsu's school day, they arrive. Todomatsu opens the back door and holds his little brother's hand the whole time he's getting out. He doesn't let go until they've ordered and are back to the car with their sweets. Once they have their food, Todomatsu gets into the back seat with him. They eat in comfortable silence. While Karamatsu's finishing off the end of his cone, the older asks "How about niichan kisses your knee better now, hm?" with a cute wink. The little one hurriedly finishes and nods quickly. Todomatsu tells him to take his shoes off and swing his feet up onto the seat, and he does so without protest. The oldest leans down and very gently kisses his little brother's knee; he peels the bandaid off and kisses the scrape itself tenderly. "Kara-touto," he chimes. "You've got another scratch up here~" he pokes at his younger brother's soft chubby upper leg, moves his face up and kisses his inner thigh. He lingers there a little too long and he knows it. "T-Totty niichan..." Karamatsu's blushing and staring at his older brother's face between his pale, soft, untouched thighs. He doesn't know why he feels the way he does. He doesn't dislike it either, though. His older brother, however, obviously notices the tiny bulge in those tight, tight gym shorts. "Kara-touto, how's it feel when niichan kisses your thighs, huh?" He plants his lips ever so closely to his little brother's crotch and sucks on the soft skin. Karamatsu whines and isn't sure what to do with his hands. "M-my... my pants feel tight, Totty-niichan..." he replies in desperation. "Well they're a size too small right?" his older brother goads, leading him along. "That's... th-that's not what I m-mean...." He doesn't know how to explain how he feels, but he asks to take his pants off and Todomatsu lets him. How could he say no to he's adorable little brother when he was so obviously bothered... The older ever so gently places his fingers over the front of his little brother's briefs. Without saying anything, he applies pressure and rubs softly. Karamatsu doesn't understand why this feels so good. His breath catches in his throat in an almost hiccup when Todomatsu presses a tad harder, and something dawns on little Karamatsu's mind. Last year in school they had something the teachers called "sex ed". Looking at all the pictures they showed in the slideshows made him feel funny, like how he feels now... but... only married people are supposed to do dirty things like this, right? "Why is Totty-niichan doing it to me?"he thinks to himself. "N-niichan are we... going to have sex?" he asks shyly and somehow innocently. Todomatsu almost keels over from how cute his smaller sibling's naivety is. He looks up from between Karamatsu's milky thighs and smiles at him. He closes one eye and places an index finger over his lips. "It'll be our secret, ok Kara- touto?" Karamatsu nods his head a little bit too enthusiastically. "Y-YEAH!! Yeah our secret! I won't tell anyone not even mom or dad or Choro- niisan or-" but he's cut short. Todomatsu has placed the gentlest of kisses on his small soft lips. "Shh, it's alright. i trust you to keep our little secret safe," He's cooing while he runs his hands up Karamatsu's midriff to his chest, and circles a finger around a small soft nipple. The little one doesn't understand why it feels so good. He thought only girls were supposed to like that, right? But he whimpers involuntarily, because it does feel good. Then, unexpectedly to Karamatsu, his older brother gently takes the nub between two of his finger and pulls lightly. Karamatsu wails and squeezes his eyes shut. His back is arched, and his hips are twitching on their own. He never thought something could feel this good. To Todomatsu's delight, his little brother is remarkably adorable when he's writhing in pleasure. "Here, let me take this off, it'll be easier ok?" He tugs at Karamatsu's gym shirt to pull it over his head. "But what about you, niichan?" he bumbles out. He's a little embarrassed that he's almost fully naked and his older brother is completely clothed. But Todomatsu takes the hint, and while Karamatsu's pulling his shirt off, the older takes his slacks off and takes the liberty of rubbing himself a few times through his boxers. God his little brother is so adorable. It's making him almost painfully hard, thinking about all the things he could do to him. Once Karamatsu's got his shirt off, he's occupying himself with staring in awe at the big bulge in his older brother's underwear. He's seen all his brothers naked before, when they go to the bathhouse together, but this time it looks so big... It doesn't look like how it does when they bathe together. Todomatsu takes notice. He makes a little show out of rubbing himself some more for his tiny audience. It feels better than it should, palming his dick through his boxers in front of his little brother. He lightly giggles at how awestruck he is despite his still being clothed. Karamatsu looks away and blushes hard when he realizes he's been found out. "Ne, Kara-touto," he pauses. "Do you wanna see it? Do you wanna rub it like i'm doing?" he accentuates it with a purposely slow stroke. "You can try it if you want." Karamatsu's lips part as if he's going to say something and then snap shut. He nods furiously with closed eyes, too embarrassed to really speak. Todomatsu spreads his legs wider and pulls little Karamatsu by the armpits to place him between his legs. He lets go of his younger brother and slowly, gently pulls the waistband of his briefs down, just showing the tip of his hard cock. Karamatsu takes a shaky breath in. It looks so flushed and... "wet? Is it leaking?" he can't help but think to himself. Todomatsu lets out a breathy giggle again at how enthralled this little one is. He continues and pulls the waistband about halfway down his cock before stopping. Karamatsu's breath catches when his brother reminds him he can touch it if he wants. He reaches out his shaky soft little hands and grips the shaft with one, and with the other he reaches a single finger out and rubs it over the tip. It's taking all of Todomatsu's self restraint to not buck up into his little brother's hands right there and then. He distracts himself a bit with working his boxers down to his thighs, fully exposing himself now. Karamatsu gasps. Nestled right between where Todomatsu's shaft ends and his balls start, there's a shiny little loop of metal, met in the middle with a sparkling pink gem. If Karamatsu wasn't completely awestruck by his brother's dick, he is now. He's staring at it, admiring it; he can't take his eyes off it. Without much thought he's asking "Does it hurt? Can I touch it? It's so pretty..." and with even less thought Todomatsu takes his little brother's hands and cups them over his sack. Karamatsu's face is burning red, but he's in no mood to stop now. He lets his fingers fiddle with the loop of metal. Twists it, pushes it back and forth. It's all driving Todomatsu absolutely wild. He's being teased so hard and his little brother doesn't even know he's doing it. It's not until a bead of precum dribbles down over his fingers that Karamatsu notices anything but the piercing. He pulls one hand away, leaving the other on his brother's sack. "It's sticky..." He's filled with wonder over this entire situation. Todomatsu shifts his leg, and his little brother jumps. He'd been straddling the older one's thigh; when it moved, it rubbed against the front of his tight white briefs. His hand tightened in response to the stimulation, squeezing at Todomatsu's balls. They both let out a soft moan together. "K-kara-touto, do you want to make niichan feel good?" Todomatsu manages to pant out. "The way you just felt when I moved my leg against you? If you do, i'll repay the favor~" he coos, almost begging. Karamatsu's so eager to feel it again. He nods enthusiastically, and Todomatsu bites his lip and smiles. He digs in his discarded pants pocket for a little bottle and tells his younger brother to put his hands out. Karamatsu complies so willingly, so cutely, it's making the older's heart jump. "Here, put your hands out spread this on them," he's saying as he's already pouring lube into his brother's tiny palms. He takes in a shaky breath before telling Karamatsu what to do next. "N-now... take your hands like they were before. Around it." Hardly before he can finish, his little brother is so eagerly doing as he's told. The older's breath hitches before he continues. "Slide your hands up and down it... and squeeze some." he's gently commanding. Slowly and with willingness, Karamatsu does as he's told. "Fuck," Todomatsu thinks to himself. He could cum right there and then if he wasn't in control. Karamatsu's starting a slow, steady rhythm, sliding his small hands up and down his big brother's cock. He watches in amazement as Todomatsu's stomach muscles clench, and while some very satisfying noises slip out of him. Todomatsu doesn't consider himself a quick shooter, but lord he might be right now with his cute naive little brother jacking him off. Before he can process what he's saying, he's already out with it. "K-kara-touto, do you want to make it feel even better for Totty-niichan?" Karamatsu stops, considers, and nods slowly. "Okay. Can you... can you kiss it for me? Like I did with your knee?" Karamatsu nervously licks his lips and stares at his big brother's shaft in his hands. He swallows anxiously and leans himself towards his brother's groin. Todomatsu shivers when he feels his little brother's soft breath on the head of his dick. Without further warning, Karamatsu's soft untouched lips are on his tip. He barely resists the urge to throw his head back, but lets out a low long moan. "K-Kara-touto, c-can you look at me now? And move your hands again?" he's asking. Karamatsu does as he's told, shyly looking up at his brother's face, his lips still resting on the tip. His face is entirely flushed, and his eyes are wide and innocent. He starts moving his hands up and down again, and oh god Todomatsu can't take it anymore. He's gonna cum from his little brother shyly kissing and stroking his cock. It's only a few more inexperienced movements from those small hands before he's cumming in thick white ropes all over Karamatsu's cute little surprised face. Todomatsu's head is swimming as he lets the orgasm ride through him, hazily watching as he spurts cum on his little brother. Karamatsu pulls back and looks... worried. "W-was that supposed to happen? Did I do something wrong?" Todomatsu is breathing hard as the coil unfurls in his abdomen. He takes a moment to sit up and pet his little brother's hair. "No, you did perfectly fine. You were amazing, little Kara-touto." Karamatsu's stained face lights up "I-I did good? Did I make Tott-niichan feel good?" Todomatsu's leaning over and reaching for a napkin as he assures the little one he did an absolutely wonderful job. He pushes his little brother's bangs back and licks the napkin before wiping his own cum off that soft smiling face. When he's done cleaning him up, he tells him to lay back. "It's your turn now, Kara-touto." Karamatsu tries and fails to hide his excitement. His older brother positions him so his back is nearly flush to the seat, his legs hooked over the other's shoulders. Todomatsu strips his little brother of the last little thing covering him. "Ready Kara-touto?" he croons, smiling, looking up through his eyelashes at that eager face. "U-uh huh," he's nodding again with enthusiasm. Todomatsu lowers his face down between soft thighs to his brother's small dick. Without saying another word, he runs the flat of his tongue along the underside. It's a small stroke, but it's enough to make Karamatsu moan shamelessly. He's already bucking his hips, he can't control himself. Todomatsu giggles and lets him. There's no warning when he wraps his whole mouth around the small thing and sucks gently. Karamatsu's thrusting right up into his mouth. It takes all of two minutes before he's close. He's erratic and inexperienced. Todomatsu lets his little brother fuck his face until he finishes in his mouth with a loud wail from the smaller one. By the time he's done, his big eyes are welled up with tears. His breath is short, he's never felt this good in his life. When he looks up, Todomatsu sticks his tongue out, showing the small bit of cum the smaller released into his older brother's mouth. The older winks and pulls his tongue back in and swallows. Karamatsu doesn't quite know why he's embarrassed by that. "Come on, Kara-touto, let's get you dressed again and back home. I bet dinner's waiting for us." End Notes hmu on twitter @todokaras Please drop_by_the_archive_and_comment to let the author know if you enjoyed their work!