
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
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