
Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/4874512.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      M/M
  Fandom:
      Ao_no_Exorcist_|_Blue_Exorcist
  Relationship:
      Mephisto_Pheles/Okumura_Rin
  Character:
      Mephisto_Pheles, Okumura_Rin, Okumura_Yukio
  Additional Tags:
      Masturbation, Anal_Fingering, Hand_Jobs, Incest, Sibling_Incest, Plot
      What_Plot/Porn_Without_Plot, Mating_Cycles/In_Heat
  Stats:
      Published: 2015-09-26 Words: 2863
****** It's Hot ******
by Youkai
Summary
     Rin goes to Mephisto for some "Friendly" "demon" "advice" about a
     little problem he's been having recently.
     (Not shameless, very shame. wow.)
Notes
     Oh god I'm so embarrassed also I love blue exorcist
     aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaah-
     I'm not really that confident in my writing, I just really felt like
     it since I was bored and love blue exorcist-
 
… So hot…
Damn it! Why is it so hot!?
 
He’d been laying there for about an hour now, slowly but surely getting more
antsy. Rin had felt this before, the familiar tightness in his pants, the flush
of his skin, the nagging need to touch himself. He knew what arousal was, but
this was different, it had never been this INTENSE before. He felt like some
kind of animal…
Worst of all was his little brother was still sleeping peacefully in the bed on
the other side of the room. It made him anxious. It was unusual, it was the
middle of the night and he was even more worried about being caught than usual.
Squeezing his eyes shut he tried to calm his rapidly pounding heart and swallow
fear of getting up to take care of it.
After a minute he slowly roll from the bed and onto his feet, holding a finger
to his lips when Kuro raised his head curiously. It wasn’t playtime now.
The moment the door to the dorm bathroom was shut behind him he let out a
relieved sigh and quickly clicked the lock on the door, finally, now to take
care of the real problem.
He took another annoyed moment to wonder what was wrong with him. Was he sick?
Had he eaten something bad? Why had his body decided to randomly act up like
this. He wondered again if this was somehow related to his awakening as a half-
demon.
Rin stepped out of his pants, flinging the shirt over his head into a pile with
his stuff.
It could be, it wasn’t like he knew that much about demons anyway, he thought
as he sat on the little stool before the showerhead. The old man had told them
about sins and stuff, and lust was one of them right? And demos were all about
that right?
Shaking his head he twisted the knob and sighed as cooling water washed down
his back. He’d been sweating something fierce under those blankets. He sighed
again as he realized that the cool water was doing nothing to calm his rampant
arousal.
Fine, it didn’t matter, either way he had to take care of it.
Rin picked up a bottle of body wash and lathered it between his hands, rubbing
them along his shoulders, down to his pecs and stomach, feeling the rather well
defined muscles and shivering at the sensation of his own hands touching his
arousal sensitive skin. A warm slightly calloused hand found his erection and
he had to bite back a yelp. It- it usually wasn’t this sensitive. What the fuck
was wrong with him?
He gasped and trembled, his gentle fingers twitching over his throbbing
erection with care. His other hand traveled across his chest, brushing over a
nipple and making him twitch, before shyly move downward toward his balls. He
grabbed them gently, using both hands now to pleasure himself, hoping to get
this over with quickly and rid himself of this unwanted arousal.
His tail swished anxiously and curled around his thigh, twitching along with
the movements of his hands.
Putting pressure on his cock hurt, making it ten times more difficult to jerk
off like this, and he was starting to feel weird other places too…
Rin squeezed himself and sped up his movements, gritting his teeth when his
body reacted to the overstimulation. Quickly, too quickly, he felt the tension
in his lower stomach curl and tighten.
He bit his lip when he came, seeing white for a minute and twitching
erratically.
After a minute or so he was starting to come down from his high, shaking his
head and looking down at the cum splattered tiles. Damn, that was a lot, and
why was he so worn out? After a while he was horrified to realize that he
wasn’t softening like he should, barely feeling any different than before.
Rin cursed and shook his head, grabbing the soap again and quickly washing
himself. He quickly made his way to the tub, filling it with cool water and
sliding in. Hopefully he could simply force his body to calm down this way, he
must have been running a stupid temperature or something.
 
 
===============================================================================
 
 
Rin returned to bed later shaking slightly from the chill of the cold
bathwater. Thankfully it had worked to calm his body down for now, so hopefully
he could get some sleep and figure this shit out the next morning.
 
 
 
===============================================================================
 
 
He did not figure out what was wrong the next morning, or the morning after
that, ect. and so on. If fact it went on for a solid week before he decided to
talk to someone. Now who could that be? Yukio would be the obvious choice, he
was trained as a doctor after all, but… No, fuck, he just couldn’t, for many
reasons, but mostly because he was fucking embarrassed and couldn’t deal with
the face his twin would probably make. It’d probably be so professional and
grown up, like he wasn’t a weirdo or anything, no.
The nurse? No, she didn’t know he was a demon. Also she was a she.
Friends? FUCK no.
If only Shirou… but no, he couldn’t dwell on that, it wasn’t helping.
He stiffened, feeling a growing sense of dread as the idea of a certain someone
who happened to be a centuries old demon with plenty of experience aaaand who
just happened to be his legal guardian at the moment.
 
Shit.
 
 
 
===============================================================================
 
 
Mephisto was looking at him weirdly (or was it just that his face was always
weird) and it was making him twitchy. Rin had knocked politely and entered,
then just stood there awkwardly for a minute.
The older demon raised an eyebrow at his younger half brother and set his pen
down, turning his attention from work to the younger demon. It was odd to see
him so nervous and shy looking, so it must have been important, “Well, come in
come in, sit down.” he guested toward the ugly (vintage!) chair in front of his
desk.
Rin awkwardly walked over to the chair and sat down, looking like he wanted to
be anywhere but here right now.
“I assume since you look so nervous that this isn’t a pleasant visit~? So what
brings you to my office today~~?” He smiled innocently, trying to put him at
ease but only making it worse really.
Rin scowled at the floor and muttered something, scratching his face and
unknowingly flicking his tail back and forth.
“I have impeccable hearing, but you’re going to have to speak up Okumura-kun~”
He flinched and frowned harder, “I SAID that I have some demon… stuff, I think,
that I need to talk to you about… “
The older demon sat back in his chair and steepled his fingers, smirking
slightly, “I see. ‘Demon stuff’. Very interesting, good on~?”
Fuck, this was going badly. He really fucking wanted to bail right now but knew
that Mephisto wasn’t going to just let him go, not when he’d dangled such
tantalizing bait in front of the old goat’s eyes.
He snarled under his breath and ran a hand through his hair in irritation, “L-
look I… It’s just that I’ve been… feeling a little weird lately.”
“Weird how?” Mephisto’s eyes dulled slightly and he looked to be resisting the
urge to roll his eyes.
“Like…” he grit his teeth, trying desperately to fight down the rather bright
blush on his cheeks, “Like really, hot, and… itchy and stuff.” Perhaps they
could actually get through this conversation without Rin having to say the word
boner? That would be great. He hoped the older demon would know what he was
getting at without having to specifically spell it out.
He was looking rather interested now, “Hot and ‘Itchy’? I see, so why have you
felt the need to come to me specifically? If it’s about a rash I’d suggest
seeing the school nurse, I’m not an official doctor after all, just a
principal~!”
Why did it seem like he was doing it on purpose? “No-Fuck, it’s not about a
rash!” Rin clenched his fingers into the fabric of his jeans, not looking at
Mephisto anymore, “Look it’s like… I’ve been having like a really hot
temperature and been feel really a-aroused without wanting to be! I’ve never
felt like this before, I mean I went through puberty and the voice changing and
all that and this problem calmed down, but now all of a sudden it’s way worse
than it ever has been before and I was just thinking that it had something to
do with awakening as a half demon and I couldn’t talk to Yukio because that’s
fucking awkward and you said you’d help me with this stuff so there!”
There was a pause of silence punctuated  by Rin’s heavy breathing before
Mephisto clapped his hands, “Impressive, I didn’t know you could say so many
words without breathing for so long.”
“Damn it this is serious!” He shouted at him, humiliation crawling up his neck
in the form of a deep red blush.
The older demon snapped his fingers and a poof appeared in front of Rin’s eyes,
revealing a lollipop, “Here, have a sweet and calm down and I’ll try to explain
your current predicament.”
Rin glared at him but snatched the lollipop anyway, shoving it into his mouth.
Mephisto smirked at him and continued, “Demons tend to have much stronger urges
than humans, so I’d say you’re most likely experiencing these changes as a
result of your body coming to accept your demonic blood more fully. After a
while you it should begin to calm down, though your urges and senses may remain
more heightened than they previously were.”
“Great,” he mumbled around the lollipop treat, “so how long?”
“That I don’t know~ I guess you’ll just have to wait! Until then maybe you
should seek a partner… or perhaps some lube~!”
 
 
 
===============================================================================
 
 
He’d left Mephisto’s office feeling pissed as hell, but slightly better now
that he knew he wasn’t dying or something. (also he’d thrown the sucker wrapper
on the floor just to piss off the clown, so that was fun)
Sadly for Rin, this was going to get worse before it got better.
 
 
 
===============================================================================
 
 
Before, these little ‘episodes’ as he liked to call them, where only happening
at night or early in the mornings, but now he was starting to feel that heat in
the middle of CLASS. He tried to ignore it, but decided he definitely needed to
leave the room when he felt his cock starting to harden in his school trousers.
He blathered some excuse to Yukio about the nurse before grabbing his things
and bolting from the room. He didn’t make it farther than the boys bathroom,
locking the stall behind him and shoving his pants down his hips.
His rock hard erection sprang up from his boxers mockingly, it was rock hard
and already dripping. Now he knew there was nothing WRONG with jerking off, and
boners were a natural part of life and shit, but DURING CLASS was not the time
when he wanted to have them!! Especially when he sat next to Shiemi. He grabbed
himself and had to slap a hand across his mouth to stifle his needy whine. He’d
been jerking off so much lately it was starting to get sore.
He began jerking at his overly sensitive member, furiously trying to get relief
from the throbbing need between his legs. Every motion only served to make him
more frustrated. He felt close, yes, but only just. It was hovering there on
the edge but he couldn’t get off! He clenched his eyes shut and curled up
slightly, trying to ignore to twitching in another part of his body.
It wasn’t working, no matter how much he jerked he couldn’t get the release he
so desperately wanted. Something must be wrong, maybe Mephisto was wrong, maybe
he really was sick.
This wasn’t happening, this wasn’t happening! Fuck he needed to get out of
here. He was gonna pass out if he kept trying. Mephisto would know, he could
help him right? Oh god he felt like he was going to explode, it hurt!
Rin stood on shaking legs and pulled his pants up, zipping up and trying
desperately to cover the bulge in his pants with his shirt. The clown was
probably in his office right now, all he had to do was get there before someone
noticed him. Right, easy, okay.
He poked his head out of the bathroom door, frantically looking both ways
incase someone was near before bolting down the hallway. It was so awkward!
He wasn’t even halfway there before he had to stop, ducking behind a dark
corner and and leaning over with his hands on his knees. Fuck! He clenched his
eyes shut and tried to block it out.
Rin couldn’t have been there long, but what he didn’t notice was that he’d been
seen. The little white dog trotted toward him quickly, looking worriedly at the
anxious young man. After a moment he poofed into Mephisto and grabbed the teen,
earning a squeak of fright moment before he poofed them to an entirely
different location. It looked like a bedroom, Mephisto’s bedroom most likely,
judging from the otaku shit everywhere. He registered the hand on his shoulder,
shaking him slightly, and looked up at his older half brother.
“What’s the matter? You look like someone’s put you through the ringer.” It was
clear that Rin was heavily aroused, but at the moment the older was unsure if
there was some other unforeseen problem for the teen looked terrible.
The smell of candy his his nose, the feel of Mephisto’s hand on him, the warmth
of a body so close to his own. He moaned and leaned heavily on the other demon,
beginning to lose himself in a daze of heat, “M-Mephi-isto… help, it’s so hot…”
The older man couldn’t help but be affected by his words, his little brother
was so cute~! He must be really in need if he was acting this way towards him.
Clicking his tongue against his teeth and picked Rin up and moved toward the
bed, “Your Aniue will help you, don’t worry.” he soothed, sitting down on the
bed and pulling the younger into his lap.
A snap of his fingers and Rin’s pants were gone, neatly folded on the bed
beside them. From looking at him Mephisto could tell he must be in a lot of
pain. His erection was red and leaking pre-cum, twitching with his heartbeats
every so often. Summoning a bottle of lube he quickly removed his gloves and
poured a generous amount onto his hand. A moment later he grasped the teens
aching erection in his hand, earning a loud moan and desperate trembles. Rin
whined low in his throat and bucked against Mephisto’s fingers, trying to get
more, and the older man didn’t leave him wanting.
He gave him a squeeze and began rhythmically stroking him, keeping it gentle
when the younger flinched slightly, “Shh… Aniue’s hear…” he kissed his cheek in
a rather affectionate manner, making the already flushed teen shudder.
Rin groaned impatiently and tried to buck against him, muffling a desperate sob
against his cavart and trying to get more, “I-it’s not working! N-naaah! I-I I
need-!”
Mephisto hummed gently and picked up the bottle again, dribbling more onto the
fingers of his other hand. Said hand traveled  down below the boys cock, to his
neglected asshole that was twitching slightly. He tapped his gently and moved
his finger into circles around the twitching muscles, earning a gasp from Rin.
After a moment of teasing he pressed the first finger in. The boy in his arms
tensed for a moment before whining and rubbing back against the feeling, he
wanted more. Happy to oblige, Mephisto pressed a second finger into and pushed
them deeper into the teen’s twitching asshole. Not long after the searching
fingers found his prostate, pressing down against the gland inside him and
making him cry out. Thrusting his fingers inside him, and stroking him off, the
boy wouldn’t last longer. He desperately clutched at his older brother, crying
out his name and other such sweet nothings as he tensed in his arms, and then
he was cumming. He came hard, letting out a choked gasp and tightening up
around the intruding fingers. Thick jets of cum spurted out of his cock and
onto the floor before the rope tapered off into shorter bursts onto the bed and
Mephisto’s fingers. Slowly his body began to relax, turning to jello in
Mephisto's arms. He tensed briefly as the hands were removed before relaxing
once more.
He figured he should feel more ashamed for this, but strangely enough the
feeling didn’t come. He looked up at Mephisto, noting how untroubled he looked.
“Um…” Rin gulped nervously.
“Hmm?” the older demon rubbed a hand against Rin’s stomach soothingly, smiling
at him and waiting for him to speak.
“... thank you.” he closed his eyes and nuzzled against Mephisto’s shirt to
hide his face.
“Not at all little brother~”
Please drop_by_the_archive_and_comment to let the author know if you enjoyed
their work!
