Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/4151394.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      M/M
  Fandom:
      Free!
  Relationship:
      Hazuki_Nagisa/Matsuoka_Rin
  Character:
      Hazuki_Nagisa, Matsuoka_Rin
  Additional Tags:
      Prompt_Fic, Underage_Sex, Time_Skips, Anal_Sex, Shower_Sex, Bathroom_Sex,
      Hand_Jobs, Omorashi, Urination, full_bladder, Barebacking, pee_kink,
      Creampie, Top_Nagisa, bottom_rin, mild_dirty_talk
  Series:
      Part 11 of Kink_Fanfictions
  Stats:
      Published: 2015-06-17 Words: 1302
****** Full Bladder ******
by wsakuya
Summary
     "Rin-chan, let's go to the toilet!" Nagisa chimes, his feet jumping
     up and down as he winds his arms around Rin's own.
Notes
     PLEASE READ BEFORE YOU CONTINUE:
     This is merely a fantasy of mine. I do not support this kind of
     behavior in real life.
     I willingly write this because I have enough brain cells to separate
     fantasy from reality.
     Just because I am writing about Underage Sex does not mean that I
     want children to fuck each other before they can't use even half
     their brains.
     If you have enough brain cells to understand this as well, then keep
     reading.
     If this is not your cup of tea, don't even bother.
     PROMPT: "I would just like to say that I love your kink fanfiction
     series on AO3! I just discovered it this morning and I love it :3 I
     was just wondering if you could write something with omorashi in it?
     (*/ω＼*) it can be with shota characters from free! or any character
     from haikyuu, whatever you feel comfortable writing :D"
     I'm not sure if I handled the omarashi well in this one. I hope it
     turned out okay? Like, I understand what it's about, but I think I
     didn't really manage to get it through in this fic. Sorry about that.
     Still, I hope you enjoy it! ; A ;
     Thank you and have fun!
See the end of the work for more notes
"Rin-chan, let's go to the toilet!" Nagisa chimes, his feet jumping up and down
as he winds his arms around Rin's own.
The boy groans, his face in a frown. "Why do we have to?"
"Because I need to pee!"
"And why do I have to come along?" Rin asks and wants to change into his street
clothes, swimming practice long over.
Nagisa and Rin are the last ones in the locker rooms since they decided to stay
behind and swim a few more races.
Nagisa takes Rin by the hand and pulls him into the showers, both their swim
trunks falling to the floor.
"Know that you mention it," Rin says and squirms. "I have to pee too."
Nagisa's expression brightens, his pink eyes shining clear.
"Then I'll help!" he says and presses his chest to Rin's back, arms winding
around the boy and gripping his limp, little penis.
"Nagisa, wha— stop—" the red-haired breathes, his chubby cheeks turning pink.
But his protests reach deaf ears as Nagisa begins moving his little hand up and
down, holding Rin's cocklet in a loose fist.
"Nagisa, that— you're making it hard, peeing's gonna be difficult like that,"
Rin mewls, but his grip is weak against the blond's hand, and he's not doing
much before he eventually lets go and watches Nagisa jerk him off clumsily.
His full bladder gives him a funny feeling, and Rin starts breathing harder as
Nagisa increases the speed of his movements.
"Does that feel good, Rin-chan?" he asks and kisses Rin's shoulders lightely,
leaves fleeting touches before changing his attention back to his hand rubbing
Rin's small penis.
"It's— yes, feels good, but I don't know why," Rin admits, his skin prickling
with heat. "When I did it myself, it wasn't like this—"
"It wasn't?" Nagisa asks and starts humping Rin's leg. "Then I'll always do it
for you, okay? But only me!"
The red-haired quietly nods, his cheeks bright pink, and he shudders as he
feels Nagisa's cock prodding at his asshole.
"Nagisa? What is that?" he asks and turns his head, a gasp escaping his lips as
he realises that the blond is as erect as him.
"Don't worry, Rin-chan, it's just gonna hurt a bit," Nagisa says and thrusts
his hips forward.
"What hurt?" Rin asks before he gasps again, feeling Nagisa's small cock
pushing inside him.
It's not big, but it's still bigger than any suppository he's ever received,
and he has to grunt quietly in pain before Nagisa's settles inside him, tiny
balls pressed against Rin's ass.
"S'okay, Rin-chan, s'gonna feel good soon," the blond murmurs and starts
jerking off the boy's penis again, his lips mouthing along Rin's neck to
distract from the pain his cock is causing.
Rin nods silently, trusts Nagisa blindly as he lets him being touched like
that; so intimate he knows he's only supposed to do it with the person he
likes.
But he likes Nagisa, likes how the boy clings to him ever so often, his blond,
curly hair and the soft skin, loves Nagisa's scent and their bodies pressed
together like this.
He starts to mewl again and throws his head back as Nagisa's cock is steadily
fucking into his tight asshole.
"Nagisa, wait, my pee—" he gasps and feels it tingling in his body, feels it
pressing down uncomfortably at the bottom of his belly.
And yet that tingling is making him feel hotter, makes the thrusts of Nagisa's
cock into his asshole much more pleasant, and he unconsciously starts to move
his hips towards Nagisa's own.
"Nagisa, feels good, my tummy feels good," he gasps as the blond increases his
thrusts and pushes deeper.
"Me too, Rin-chan, my weenie feels amazing—" Nagisa pants as he grips Rin's
hips tighter and presses inside again, his full bladder arousing him as well.
It's getting harder to thrust as Nagisa can't keep his pee back anymore, the
pressure almost unbearable.
"Rin-chan, I gotta pee— Can I pee, Rin-chan?"
Rin nods breathlessly, his hands wound around Nagisa's arms, and he mewls.
"Pee, it's okay—"
"Here I go, Rin-chan, gonna pee—"
"Wait— In my butt!?" the red-haired gasps, and he starts to push Nagisa away
with his weak hands, without success.
"Rin-chan, Rin-chan, Rin-chan—"
With a long moan, Nagisa empties himself inside Rin's asshole, squirts his piss
in the tight walls and marks them thoroughly.
"Nagisa, no, my butt—"
Rin feels the juice being pumped into him, feels it fill his belly before
coming himself, spurting his pee onto the shower walls and watching the yellow
liquid run down the white tiles as he mewls through his orgasm.
Nagisa's pee is too much for his little belly, and before he can react it's
already squirting out of his asshole and running down his legs.
Rin shudders quietly as he leans his hand against the tiles as support, Nagisa
pressing onto his back.
"Rin-chan, that was amazing," the little boy breathes, his arms still wound
loose around Rin's torso.
Both their legs are shaking, but it was worth it, because Nagisa's sure, peeing
has never felt this good before.
 
                                     EXTRA
 
"Rin-chan? You feelin' good?" Nagisa breathes into his ear, chest pressed
against back as he rapidly fucks into him.
There are slapping sound as he keeps thrusting in and out, his balls hitting
the crack of Rin's ass.
Rin's mewling quietly, trying so hard to keep his voice in, but with the blond
fucking him as hard as possible and hitting his prostate over again, it's just
impossible. His legs are already shaking from standing up and leaning over the
toilet, and he probably would have collapsed a while ago if it wasn't for
Nagisa's ridiculously strong arms holding him by the hips.
"Gotta piss, Rin-chan?" the blond asks, breath dancing over Rin's neck and
making him shudder as he nods, his bladder so full he feels like exploding. But
exactly that feeling causes him to get so hard and hot, causes him to moan like
a bitch in heat and move his hips towards Nagisa's thrusts.
Nagisa grins, his pink eyes shining with arousal. "Yeah, me too, Rin-chan—
Gonna empty myself inside you, fill you up nicely and cover you in my piss—"
Rin shudders as he feels himself losing control over his bladder, the feeling
in his stomach getting stronger and stronger with the need to finally let go
and relax his belly.
"How about sucking me off then? Sucking my cock off while it's covered in my
piss and your ass juice, hm?"
"Anything, but please, piss inside me, Nagisa— Fuck, make me round and fat—"
Nagisa grips Rin by the hips tighter, groans at those sweet words only for him
and speeds up, the slapping sounds turning louder in the small bathroom.
Rin starts to moan louder, his mouth standing wide open and shark-teeth on
display as he drools into the toilet under him, listens to the splashing sounds
that arouse him only more, and with Nagisa's name on his lips, he comes long
and loud, Nagisa pointing his cock in direction of the toilet as he lets go,
lets his piss shoot out of him and fill the toilet.
"Fuck, Rin-chan, so tight— Gonna fill you up now, okay? Mark you in my piss,
make you mine, Rin-chan—"
Nagisa follows suit as he empties himself inside Rin; first his come, and then
his piss, filling up the male thoroughly.
Rin watches breathlessly how his belly's slowly growing as Nagisa fills him
with his juice, coats his walls and makes him nicely fat.
The toilet and the floor are now completely dirtied by their piss, but Rin's
only smiling tiredly as he leans against the toilet.
"Glad we could do it again," he says, feeling Nagisa lean his forehead onto his
back.
"Same here, Rin-chan."
End Notes
     (I'm not forcing you to comment on this work since I know that many
     people feel uncomfortable with commenting on sexual-themed
     fanfictions, so I would be happy if you left a kudo. Thank you!)
     PS: Send me a prompt, http://wskprompts.tumblr.com/ask
     If the ask box should be closed, then it's because I'm taking no
     prompts at the moment. Please be patient and wait for my next post,
     and then check my ask box again.
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