Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/10099223.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      M/M
  Fandom:
      ダイヤのA_|_Daiya_no_A_|_Ace_of_Diamond
  Relationship:
      Kominato_Haruichi/Kominato_Ryousuke
  Character:
      Kominato_Haruichi, Kominato_Ryousuke
  Additional Tags:
      Underage_-_Freeform, Haruichi_is_in_his_last_year_of_middle_school,
      Sibling_Incest, Incest, Alpha/Beta/Omega_Dynamics, Omega_Verse
  Stats:
      Published: 2017-03-05 Words: 3968
****** Early Bloomer ******
by Falan
Summary
     Haruichi was first in his age group for everything it seemed. And
     presenting was just something else to add to the list. Luckily his
     brother seems not to mind too much this time.
Notes
See the end of the work for notes
This was the most uncomfortable and hot Haruichi could ever remember being.
Stripping down to nothing didn’t seem to help at all, even with only the sheets
touching his body he was burning. The top sheet covered his sweaty figure only
to keep a little modesty were someone to walk into the room; not that they
couldn’t tell what was happening to him even if they didn’t enter the room. His
scent was probably seeping all over the house from the crack under his door.
And the sounds coming from his room could not be mistaken for anything other
than what they truly were. He wished he would have the courage to toss the
sheet off of his body but he still had a bit of mind to keep modesty.
His body had been aching since early that morning. Haruichi had woken to a
sharp stomach ache. He tried to sooth it in the normal ways but nothing would
touch the ache. He had even tried to cause himself to be sick to see if that
would help; it had only caused his throat to burn with stomach ache and his
abdomen to ache more. Soon the ache moved in his body. His hips were sore and
his legs itched. His head was swimming. His body had been aching for things
that had barely crossed his mind before. He should have known since he woke up
that morning what was happening. His parents had been just barely preparing him
for his possible presentation but none of them thought it would be this soon.
His mother of course had been thrilled after she raced to his room to see what
causing his groans of pain. Their suspicions had been true, even after they had
confirmed it at his birth. They now truly had an omega in the family. His
brother was an alpha; there had never been any question after his birth and
growth. Haruichi had been the slight question. Even though their doctors had
confirmed that his body had the proper antimony for being an omega he could
have easily still been a beta. It would all depend on if his hormones and his
development. It seemed all was well and he was indeed a proper omega, one that
his mother had been hoping he’d be.
Later on Haruichi was a bit more mortified when his father told him he’d be
going to the supply store and picking up the things that his youngest son would
need for his heat and after. That meant his father was going to be picking out
supplies to help the itch growing inside him and birth control. He had been
busy trying to keep his hands from his body to really respond. His mind was
focused on the ache he felt between his legs and the cramping that turned his
stomach. His mother had asked if there was an alpha he wanted to spend it with.
No one had come to mind, barely anyone of his age had presented and none of the
ones that had really catch his interest. He didn’t really know a lot of older
alphas, only his brother’s friends and there was no way he would ask any of
them. That decision shouldn’t have been made with the hormones swiftly running
through his body anyway.
When both of them had finally left him alone, with promise of rare
interruptions, he had quickly stripped his clothing wasting no time in
exploring his body or the new sensations. His nipples were so sensitive it was
almost painful as he passed them only brushing lightly against them. His cock
was so hard it leaked against his stomach. He tried that first, wrapping his
hand around his cock trying to get some relief. He stroked a few times but the
feelings he normally felt were nowhere to be seen. He just needed something
inside of him. Fingers were his obvious first choice. He flipped over and
rested on his knees almost instinctively. One finger quickly found its way
inside of him, he had groaned at the feeling finally something was helping the
ache, but it wasn’t enough. Two did better but still the feeling was too much.
Three, much better. The stretch was something that he found pleasure in.
His inside channel was hot and so slippery. He wondered briefly where it all
had come from but it fled his mind as he touched a place deep inside him that
made his toes curl. That feeling was amazing! He wished to feel it again but he
couldn’t find that place, his mind wasn’t able to concentrate enough to
remember where it was. Instead he kept pressing in and out of the soaked
opening hoping for some relief. He tried to slide his pinky in along with the
other three fingers but the stretch was too much, it hurt for the first time
that day causing him to release a whimper. He quickly readjusted himself and
plunged his fingers back inside without the added fourth.
The door opening caught his attention and he twisted his body so he could see
who had entered his room. He figured it was his mother again to check on him or
his father returning with the supplies from the store. But no, that was not the
case, he felt his cheeks heat and he tried to hide his body more under the
sheets. He curled in on himself but kept the fingers in place. His brother was
in the doorway holding up a plastic bag, his usual grin on his lips. How had
all of them forgotten that he was coming home for the weekend? Haruichi stuffed
his face in his pillows, not from embarrassment, which there was plenty of, but
to keep his brother’s alpha scent away from his nose. Even the brief hint of
the fresh alpha scent had caused a quick release of slick and a whimper to fall
from his throat. It wasn’t necessarily frowned upon for relatives, even
siblings, to mate together but it was uncommon. But he couldn’t bear begging
his brother to take him.
“Always the early bloomer, Haruichi.” His brother sounded different, the
emotion in his voice Haruichi couldn’t exactly pin down, it seemed to be a mix
of smugness, carefulness, and concern. It probably wasn’t the best image he had
ever given his brother. Knees under him, face pressed into a pillow, fingers
buried in his channel and a thin sheet covering him. Even though his face was
pressed firmly into the pillow the scent of alpha was starting to seep in. The
discomfort grew in his abdomen and he ached to move his fingers again. “Dad
told me to bring this to you.” He could hear Ryousuke’s breathing getting
heavy. His brother’s feet were scuffing against the floor as he seemed to drag
himself closer to the bed. “You smell amazing.” He whispered. Haruichi didn’t
even think Ryou noticed that he had said it.
The bag was set on the bed and Haruichi watched his brother from the corner of
his eye with his head still mostly covered with the pillow. The older boy
didn’t move from the side of the bed like he was hesitating, his hand twitching
by his side. The younger brother trailed his eyes up to his brother’s face. His
eyes were blown wide and he seemed to be taking deep breaths through his mouth.
There were beads of sweat starting to form on his brow. His face looked just as
wrecked as Haruichi probably did, no Haruichi was probably worse.
“Ryou-“
“Let me touch you Haruichi.” The request came as a shock even though his mind
had worked out it was probably going to come not to mention his body had
started to crave more than his fingers. He didn’t understand why his parents
thought it was a good idea to send his brother up with the supplies. Maybe they
didn’t realized what would happen or maybe it was their plan all along. “Let me
help you.” Haruichi’s mind tried to wrap around the idea of his brother being
the first one to take his body, to be the first one to spend his heat with him.
It seemed odd but also kind of right. Ryousuke had been the one to introduce
him to almost everything in life. Had been there to hold his hand and encourage
him early in life and push him when he had taken up baseball; in his own way of
course. But could they take this step?
“Yes.” He finally muttered lifting his head. His nostrils filled quickly with
willing, aroused alpha scent which made him let out a loud groan, nothing but
pure alpha, a heavy dose of slick working it’s from his body. His brother
didn’t waste any time once permission had been given to crawl onto the bed. The
mattress dipped and there were soon hands pulling away the sheet covering his
body. Haruichi didn’t have time to be self-conscious about being caught with
his fingers deep inside himself because the growl that came from his brother
sent spikes of pleasure through his body and his back arched almost on
instinct.
“So dirty Haruichi.” Ryousuke muttered his own fingers tracing around where the
younger’s were stuffed inside of his stretched entrance. The younger let out a
soft squeal when one of his brother’s fingers entered into him alongside his
own. This stretch wasn’t as bad as it had been with four of his own fingers but
it was odd feeling; a finger inside him moving separately from his own. The
younger brother couldn’t help when his knees slipped further apart, allowing
more room in-between his already spread legs. Haruichi can hear his brother
hiss out a breath. “So pretty Haruichi. You’re going to look so good spread on
my knot.”
Haruichi let out a moan at the thought, his body giving another large release
of slick from its depths. His brother started to move his finger inside of him,
sliding around the inside of the stretched rim feeling the slick channel. The
omega wondered for a moment if his brother had done this before or if this was
the first time for both of them. Of course he wasn’t able to voice his question
when a sharp bite came to his lower back almost directly above the swell of his
bottom. He let out a whine and his own fingers slipped from his body.
Ryousuke’s single finger felt like nothing now, his body almost felt completely
empty and it made the ache deep inside him increase.
“Please Ryou!” His hips pressed back shifting from side to side hoping to
entice the alpha behind him. All it got them him though was the finger being
pulled from inside of him and two hands gripping onto his hips as the alpha let
out a low growl. Haruichi let out a scream when a brutal bite came to his
shoulder blade. He hadn’t even noticed that Ryousuke had moved forward and was
leaning just a bit over him.
“Bad boy Haruichi.” Hips pressed into the omega’s own but they were still
covered in fabric. Haruichi let out a soft whimper as the rough material rubbed
against his sensitive skin, though if he had the choice between pulling away
and pressing closer he would have arched his back more making sure that he
would be able to feel the clothed cock under his brother’s pants. He was sure
that Ryou was getting slick all over the front of his pants with how hard he
was pressing against him even without Haruichi’s help. “You know who’s in
charge.”
“Yes alpha.” The younger brother’s voice was breathy, complete submission
coming across in his tone. He felt another, gentler, nip come to his back, this
time close to the base of his neck. “Sorry alpha.” It felt strange to call his
brother by that title. He had always been Ryou, Ryousuke, brother, big brother.
Now there was a more intimate name to add to the list, whether or not he would
use it more than this one encounter only time would tell. Ryousuke seemed to
reward him for the apology, suckling starting on the back of his neck.
“How long have you been opening yourself Haruichi?”
“Don’t know. Seems like ages alpha.” He was surprised how coherent he was. He
had heard once you were in your heat your mind didn’t work anymore, well
besides begging for an alpha and pleading to be filled with pups. Haruichi
could feel the need to say those words, to beg his brother to fill him finally,
to stretch him to his fullest on his knot, to claim him. His breath hitched.
That thought hadn’t crossed his mind until that point. What if Ryousuke claimed
him? They’d be mated. He’d be mated to his brother.
“You smell so good omega.” Ryou’s nose buried itself into the side of his neck
where one of his scent glands was located and took a deep breath. “I always
hoped you’d be an omega.” Kisses fell onto the scent gland in his neck; he
never knew that it would feel so erotic. Shivers ran down his spine making the
hair on his body stand on end. The body and hands removed themselves from
Haruichi and the sound of clothing being discarded reached his ears. “You’ve
already made me a mess Haruichi. I’ll have to have dad buy me a new uniform,
your slick is all over this one. It’d drive everyone at school crazy. Everyone
would be so jealous.”
“Ryou, don’t be mean.” The younger brother managed turning his head a bit to
look at the older boy behind him. It had been years since he had seen anything
more than a glimpse of his brother’s skin, now it was all out in the open. He
was bigger than Haruichi remembered, his muscles more defined. He could
probably attribute that to age, physical activity, and having presented as an
alpha. Haruichi ached to feel, the flesh of his brother’s body against him.
“I’m not being mean omega.” Haruichi could almost hear the smirk in his
brother’s voice. “Only stating facts.” The younger let out a whine when finally
bare skin touched his own when Ryou laid over him. “They’d all be jealous that
I had a pretty omega to spend my weekend with, one that smelled delicious and
fertile and was ready to be filled with my pups.” Ryou’s hand had moved to
stroke his stomach with the last statement. It made Haruichi pant and whine at
the thought. He’d be filled with Ryousuke’s pups. They’d grow and extend his
abdomen. He’d have something of Ryousuke’s growing inside of him, lives that
they had made together. Haruichi shook his head, even if his body liked the
idea as seen by the more heavily leaking of slick from his entrance, he was
still too young to even be thinking of wanting pups. He just needed this deep
ache to go away and his need to be fulfilled. Pups would come at a much later
time in his life.
“Ryou.” Haruichi sighed out heavily when the body trapping him to the bed moved
against him. His brother’s hips had started to rut against him just slightly,
he didn’t know if his brother was even aware of the development, his nose so
deeply buried in his shoulder and neck where his scent gland was, breathing
deeply. For the first time Haruichi was able to feel his brother’s bare cock.
It felt huge pressing and sliding against and between his legs. He was much
bigger than the omega in that area. Haruichi had half a mind to question how
his brother dealt with that between his legs all of the time.
Ryousuke shifted his stance; in doing so his cock was able to catch on the
younger’s entrance. Both of the brothers groaned and Ryou’s hips stuttered
trying to drive his cock into the wet and waiting entrance. The cock slipped
free and the tip ran down between his butt cheeks pressing against his balls
from behind. Ryousuke cursed, his hands going to grip tightly at the omega’s
hips.
“Haruichi, don’t move!” He growled at the omega.
“Didn’t!” Haruichi whimpered as teeth sunk into his shoulder. They weren’t
anywhere near where a mating claim would take place but it still sent harsh
shivers down his spine. The bite was accompanied by another deep growl. Ryosuke
moved the body beneath him how he wanted it. Haruichi’s legs were spread more,
a hand on his stomach made his hips be pressed upward, the body laid over top
of him made sure that his shoulders were pinned to the bed.
“Be a good omega.” The alpha stated once he had finally let go of the brutal
hold he had on his brother’s shoulder. Haruichi quickly nodded his head in
response his body strung tight with anticipation.
Ryousuke finally removed his hand from his brother’s stomach to grasp his cock
so that he could line it up with the dripping entrance into Haruichi’s body.
This was the moment they had both been waiting for, the slow breach into the
overheated body. Haruichi tensed his muscles when just the tiniest hint of
stretch from his brother’s cock but the growl he got in response made him relax
his muscles or try to at the very least. The alpha wasn’t taking anymore
chances. He pushed his cock straight into the waiting channel, not stopping
until his pelvis was pressed firmly against the omega in front of him.
Haruichi let out a muffled scream at the breach into his insides. The pain was
sudden and scorching. The ache was deep and caused him to tighten his muscles.
Ryou let out a growl at the tight grip, his fingers tightening on his brother’s
hips. The younger didn’t know why people found this enjoyable. So far it hadn’t
done anything to quench the fire inside of him, just added a different pain to
the mix. His hands gripped the sheets of the bed so tightly that he was afraid
he’d rip them. He didn’t understand, omega’s were supposed to like being
mounted by an alpha, this was what they were made for. Maybe he was too young,
maybe his body was too small yet to handle the stretch of an alpha cock.
His brother held himself within him, his hands gripping tightly his hips.
Ryousuke’s breathing was rapid, puffs of air falling over his throat and
shoulder. He let out a long groan and Haruichi could already feel the cock
inside of him growing. This wasn’t going to last long, he just hopped that it
would at least mute the ache inside of him for a while.
“Feel so good Haruichi. Such a good omega.” The older male pulled his hips back
only slightly before pressing back firmly into Haruichi. A yelp fell from the
parted lips of the omega, his chest filling with a sense of pride at the praise
with an alpha seated so far within him. “You’ll look so cute full of pups.
Stomach distended growing with my pups.” Ryousuke’s hand moved to travel across
his brother’s stomach as he mused, the flat muscles tightening. Haruichi
couldn’t see it but a smile twisted his brother’s lips. “Mother and father
would be so proud, they wouldn’t have to share them with anyone else. We’d make
strong pups together Haruichi.” That caused a whine to tear from the younger’s
throat.
“Alpha please!” Haruichi whined, his hips pressing back. Ryou leaned down and
nuzzled his nose against the scent glands in his neck, releasing more of the
heat scent into the air. He could feel the older boy shiver above him, a happy
sound coming from his throat. His grip became softer as he took to rocking his
hips into Haruichi. The omega could only guess that the scent had calmed down
his brother. Even with the more gentle grip on his hips his brother took to a
more savage thrusting into his body.
The omega didn’t know what had changed but all of the sudden bursts of pleasure
were raking his form. He couldn’t keep his voice down even knowing their
parents were probably still in the house somewhere. He tried to move his hips
to meet Ryousuke’s thrusts but the alpha was already moving them the way he
wanted. Ryou’s hands guided the omega’s hips forward and back depending on how
his own hips moved. Haruichi was left to claw at the sheets allowing his body
to be manhandled.
The smaller male could feel his brother’s knot growing inside of him, he felt
the stretch as it was tugged from his body and then forced back inside. The
repeated pressure at his rim and insides was maddening. The omega twisted in
the alpha’s hold, trying to force him to stay in place inside his body. It was
right there, he could feel the ache inside of him dull when the partially
formed knot was in its proper place.
“Please alpha! Knot!” He whined when Ryousuke once again took a strong hold of
him, his bite digging into his shoulder as he laid over his back. Haruichi had
a brief thought run through his head that he was going to look like he had been
ravaged by an animal after all this was done. Everyone at school would know
about what happened. At the moment he couldn’t bring himself to care. The itch
was almost scratched.
Instead of giving a response the older brother just let out a snarl. The deep
sound sent pleasant shivers through Haruihci’s body. But the verbal response
was nothing compared to the moment that Ryousuke stopped pulling his cock most
of the way from the omega’s body and started with deeper small thrust, the
still growing knot staying mostly inside. That’s when the experience started to
feel like the best Haruichi felt in his whole life. There was a pleasant warmth
throughout his body. His mind emptied of every care, every worry, everything
except for the point where he and his brother were connected.
Haruichi’s orgasm took him completely by surprise, his body running cold for a
split second then overcome with warmth. He let out a loud wail as his body
tightened around Ryousuke’s and his cock finally released against the sheets.
His world went dark for a moment, when he came to his brother was pressing
himself as deeply as he could inside of the omega and letting out a loud moan.
He felt extreme heat filling him, the knot finally locking them together
completely so there was no where for the hot liquid to go. It pooled inside of
him, spurt after spurt of hot seed filling him.
They both held still panting, Ryousuke leaning down so that his forehead rested
against his brother’s shoulders. There were soon small kisses being rained down
on the omega and soft words of praise. It was nothing like it had been when
they had been in the midst of coupling. The older slowly started to move them.
He was careful with Haruichi as he laid them on their sides. Ryousuke’s knot
still locked them together so it was difficult not to just flop over and hope
for the best. His touches were gentle, just light pressure, they switched to
petting as soon as they were both comfortable.
The ache inside of Haruichi was gone for the moment. All he felt was exhaustion
and a full feeling. He was slowly drifting off to sleep with the praise of his
brother in his ear. Maybe heats weren’t so bad, especially if you had an alpha
to help you through them he thought snuggling deeper in the soiled sheets.
End Notes
     So this took far longer than I thought it would. And theres probably
     mistakes. But eh. Its out of my system now.
     I was thinking about doing a series of Omega Haruichi but we'll see
     how that goes.
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