Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/9526412.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      M/M
  Fandom:
      モブサイコ100_|_Mob_Psycho_100
  Relationship:
      Kageyama_"Mob"_Shigeo/Reigen_Arataka
  Character:
      Kageyama_"Mob"_Shigeo, Reigen_Arataka, Original_Male_Dog_Character(s)
  Additional Tags:
      Dubious_Consent, Manipulation, beastiality, Blood, Vomit
  Collections:
      Mob_Twitter_NSFW_Gift_Exchange
  Stats:
      Published: 2017-01-31 Words: 4656
****** Doghouse ******
by orphan_account
Summary
     A couple months after Reigen and Mob first meet, they find themselves
     at a kennel for an exorcism. Reigen thinks Mob has just the thing
     they need to expel the spirit.
     Warning: Contains explicit beastiality.
Notes
     I don't condone this stuff irl but I'll be damned if I don't enjoy
     writing it.
     Also, this is severely unedited. I'm shit with deadlines.
See the end of the work for more notes
The kennel was loud; dogs barked in a cacophony of sound that shook the bones
in Reigen’s body from the inside out, but he stood firm in the center, one hand
in his pocket, the other beneath his lower lip.
“Can you feel anything in here, Mob?” He asked, dropping his hand and turning
around to face his student. The boy was squatting by the cages that housed the
smaller dogs. With the way his school bag obscured much of his form, he looked
tiny enough to fit in beside them.
“No, Shishou.” Mob replied as he shuffled forward and reached his fingers
through the chain links to scratch at the soft, white fur of the dog baring his
stomach to him eagerly. Mob’s voice was high enough to cut through the chorus
of barking that otherwise made Reigen’s ears feel as though they were stuffed
with cotton.
“Really now…” Reigen said, swinging back around to face his client. The kennel
manager raised an eyebrow.
“You think some ten-year-old would know better than me?” The man said, crossing
his thick arms over his chest and raising a bushy eyebrow. His skin was scarred
with countless scratches and bite marks that only appeared to end where his
clothes began to cover him. His eyes were hard, and critical. Reigen was maybe
as tall as his chin.
“… He’s been wrong before.” Reigen said, brushing a damp hand through the air
between them easily. A thin bead of sweat slid down the back of his neck. He
called over his shoulder after a moment, but not before discretely hiding the
path of sweat with a hand as he scratched at his neck. “Come over here, Mob.
See if you think there’s anything over this part.”
The boy stood up, withdrawing his thin fingers from the cage before him as he
did. When he made his way to the two adults standing in the center of the room,
he scurried across the floor in the center, careful to keep an equal distance
from the cages on both sides of him. When Mob arrived at Reigen’s side he clung
to his pants with his tiny fingers in tiny fists, bunching up the fabric as he
shed away from the gnashing teeth and glaring eyes. He looked a little like a
terrified lamb.
Reigen knelt by him with a smile on his face. “Mob, are you sure you don’t
sense anything out of the ordinary in here? You want to help our client,
right?”
The little boy nodded his head and squeezed his eyes shut as Reigen spoke, as
if he were trying to block out all the other sounds that fought for his
attention. Reigen had to smile at this, at least a little. It was kind of cute
seeing the kid so spooked. He gave the top of Mob’s head a firm pat and stood
up to face the kennel manager, and kept his fingers in Mob’s dark hair to
ruffle through the soft strands absently. “He’ll give it another go.”
“Uh…” Mob fidgeted, keeping his fingers tight in Reigen’s pants. The kid was
shaking beside him as if the echoes of the dogs barking were causing him to
vibrate. “That one, right there.”
Mob’s tiny, thin fingers pointed to a large dog towards the back of the room.
Reigen craned his neck to see around their thick client, and let out a low
whistle.
The dog’s head easily rose above Mob’s. His shoulders were powerful, and his
back legs looked strong enough to jump the gate that caged him in. Out of all
the dogs in the room, he was the only one that stayed silent, but the moment
his observant, chocolate eyes landed on Mob, his jaw opened up and he began to
pant.
“That dog.” Reigen said, stepping around the manager to confront the animal.
Mob scurried after him and clung to his shadow, a thin sheen of sweat sticking
his bangs to his forehead.
“Oh, you mean Brutus?” The manager said, walking over to the cage where the
animal was housed. He kicked the cage and whistled, trying to call for his
attention, but the dog did not break eye contact with Mob. “He came to us last
week.”
“Didn’t you say that was around the time when all these supernatural
occurrences began?” Reigen asked. He squatted in front of Brutus and ducked his
head down, as if he were looking for a sign of possession. “I think that’s a
pretty significant coincidence. Right, Mob?”
Behind him, Mob jumped straight out of his pale skin. “R-Right, Shishou.” The
boy said. He refused to come any closer to the gate, and seemed quite
comfortable maintaining the five feet of distance he had between himself and
the dog. “There are no such things as coincidences in the world of spirits,
and… And such.”
“Good boy.” Reigen said as he inspected the dog – which appeared to him to be
absolutely regular. Aside from the pair of massive balls that hung heavy
between its back legs, that was.
“Are you going to ignore everything I just told you about the curse my employee
found written out in blood? You know, the one that was left on our front door
on the exact day the occurrences began?”
“Well, sometimes things like that can be a distraction.” Reigen said, looking
over his shoulder at his pale and clammy student. It was almost sad how
terrified Mob looked. This poor kid, he needed someone to help him get over
such fears. Good thing he worked for a generous man. “Spirits are highly
intelligent. It’s very likely that this one laid that curse down as a diversion
to cover up his actual whereabouts.” 
“So what if the spirit is in Brutus?” The manager said, cutting between Reigen
and the dog, finally offering Mob some cover by blocking the canine’s line of
sight. The boy sighed with relief and wiped his brow. “What are you suggesting
we do about it then? You know he’s purebred? I’m hoping to get a lot out of
him.”
“Get a lot out of him, you say…” Reigen said as he stood up. He brushed his
hands down over his suit jacket to smooth out the wrinkles. “Well, luckily for
you, Mob and I can help you do just that.” Reigen snapped the lapels of his
jacket into place with a sharp tug before sticking an arm out dramatically to
point past the manager to the dog behind him. “I’m sorry to tell you this, sir,
but that dog is possessed. Thank god you called us here when you did, or you
might have found yourself in quite the predicament. Mob?” Reigen asked, turning
around to look at the boy. “I know you’ve only done this once or twice now, but
I think I’ll let you exorcise this one. That sound okay to you?”
The boy swallowed and gripped his backpack straps tighter in his hands. “O-
Okay, Shishou…” He breathed.
“Then it’s settled.” Reigen said, facing front once more to look at the bear of
a manager that squinted at him dubiously. “I’ll take the specimen and my
student out back – this might get messy.”
“Well, alright.” The manager said, dropping his arms with a sigh and shaking
his head as he walked to a wall to pick out a study leather leash and a thick
metal choker. “But I’m not paying if this won’t do shit.”
“Don’t worry,” Reigen said as he smiled down at Mob, “I’m an expert.”
 
===============================================================================
 
The asphalt lot behind the kennel was cracked and crumbling. Small weeds
sprawled over the worn tar like a ragged carpet. Small green sprouts climbed up
mangled poles and overflowed from the cracks that split the ground every step
or so. The smell of night air was refreshing, and Reigen took a deep,
enthusiastic breath. The leash in his hand whipped wildly in the air as the dog
shook his coat.
Mob kept his distance from the dog by securing himself at Reigen’s other side.
Now that they were out of the kennel, Brutus seemed to have little interest in
the boy, and instead was busy pulling Reigen’s arm out of his socket in an
attempt to drag him towards the sparse line of trees that began at the opposite
end of the lot. The leaves rustled easily in the cool breeze, and the dog
lurched forward with a strangled huff until he stood for a moment on his back
legs with the leash pulled straight between his neck and Reigen’s firm hand
before falling back to the ground and trying once more.
“Let’s move into the trees a little.” Reigen said, looking around in an offhand
manner. “There might be a better spot to perform the exorcism in.”
“Okay.” Mob said, wiping his brow and the back of his neck. Now that they had
escaped the barrage of barking from all sides, the boy had relaxed a little;
enough to walk beside Reigen towards the trees without gripping at his suit
like a vice. He would still have to iron it later.
After they had taken their first steps into the thin woods, Brutus dutifully
jammed his nose into every bush that rustled. Reigen let him tug at his arm
wildly without care; things might go easier for Mob if the dog winded himself
first, even if only a little.
Eventually the woods grew thicker, and they paced into a clearing of sorts. The
trees around them were heavy with leaves and the ground was soft and springy.
The late spring moon was high in the sky, and it bathed the ground in cool
white light where it slipped through the cathedral of branches overhead. A
single tree lay broken across the middle, splitting the clearing in two, and it
lay carpeted in soft green moss.
A sturdy branch jutted out from the trunk, and Reigen tethered Brutus to the
tree with a few tight knots. The dog nosed around the base of the tree and the
sound of his wet snout snuffling in the twigs and grass filled the silence
between Master and student.
“Are you sure I can do this?” Mob asked, shrugging his backpack off his
shoulders and laying it far from the dog’s prying nose. “I’ve never exorcised a
spirit from within something before.”
“I’m positive you can!” Reigen said as he took off his suit jacket and laid it
over the tree. “Especially in a place like this. All the energy around us is
perfect for the job.”
Mob’s brows pulled together under his bangs and he turned around to survey
their surroundings once more. “I guess that’s true.”
“That’s the spirit!” Reigen said as he unbuttoned his cuffs and rolled his
sleeves up his arms. His eyes were on Mob the entire time, taking in his
slight, small form. Brutus whined to their side, and he turned around to see
the dog straining to reach a rabbit skittering through the brush. Once again,
the first thing that caught his eyes were the pair of balls hanging between his
legs. He loosened his tie.
“Exorcising a spirit from within a creature is a little different than taking
on one by itself, though.” Reigen walked over and squatted down beside Brutus
and smiled as he scratched behind his ears. Even compared to him the dog was
tremendous. “It involves a little more work.”
“What kind of work?” Mob asked. His voice cut through the night in a clear,
high tone, and for a second all Reigen could think about was the fact that he
was a middle schooler.
“C-Complicated work.” He stuttered, stroking down the dog’s back. Brutus soon
calmed down and sat beside the tree, swinging his great head around to look
past Reigen at the boy. His mouth fell open and his tongue lolled out, and he
began to pant yet again. Reigen exhaled slowly and shook his head clear. “Why
don’t you come over here and greet Brutus? I feel like you should get to know
him before we begin.”
Mob hesitated in the center of the clearing, but soon enough the sound of his
feet pacing slowly towards the tree pulled a grin to Reigen’s lips.
“That’s it.” Reigen said, moving aside to allow Brutus a full view of the boy.
The dog stood up and wagged his tail, high in the air, and panted a bit harder.
Mob stood just behind Reigen, who had straightened up to put a reassuring hand
on Mob’s head. The boy reached across his front and clung to his white shirt,
and Reigen could feel the warmth of his body through his clothes. He took a
deep, calming breath through his nose.
“He’s much bigger than any dogs I’ve seen before.”
Reigen let his eyes slip between Brutus’s legs, and his eyes widened
momentarily when he saw the dog’s thick dick, fully erect, twitch a little when
he stuck his large wet nose right into Mob’s crotch.
The boy yelped and turned his face into Reigen’s stomach, and the man nearly
doubled over with the force of lust that winded him suddenly. Shaken, he carded
his trembling fingers through Mob’s soft hair.
“Yeah, he is a bit big.” He said, sliding a hand down Mob’s neck to his
shoulders and arm. He didn’t miss the shiver that brought goosebumps to Mob’s
skin when he slowly squatted down beside the boy. “You can touch him.” He
mumbled, guiding Mob’s reluctant hand to the top of Brutus’s head. The dog
whined and pulled at the leash, and licked heavily at Mob’s thighs.
“S-Shishou!” Mob gasped, withdrawing his hand to clutch at Reigen’s collar
desperately as his hips wiggled to avoid the sensation of a broad, warm, wet
tongue sliding over his pale skin.
“Shh… It’s alright, Mob.” Reigen said, biting his lip as he brought a hand down
to Mob’s hip. Before he even realized it, his fingers began to bunch up the
fabric of Mob’s shorts, granting the eager dog more access. Mob whined and
shivered, but Reigen was hypnotized by each new inch of skin he saw. Mob’s
shorts cut into his thighs and left red marks, and the layers of saliva Brutus
left over his skin had Reigen nearly drooling, himself. ‘I think he likes you.”
Mob bit down hard on his bottom lip, and Reigen watched as blood bubbled up
under his white teeth.  He shifted a little to watch it from a better angle,
and only then did he realize how hard he was. He winced – it was starting to
get painful.
Time to get this show on the road…
“You wanna help him, right Mob?” Reigen asked, reaching around with his free
hand to pet the top of Brutus’s head. The dog looked up from his work and
whined as he pawed at the ground, tearing up moss. Mob shivered and moved to
stand in front of Reigen in an attempt to put as much space between him and the
dog as he could in his caged in position. In this position Reigen could just
imagine his ass forced back, tight against his cock, and he squeezed Mob’s
thigh in his large hand appreciatively. “That’s something only you can do.”
Mob whined and shimmied his hips, trying to retreat further into Reigen’s arms.
“What do I have to do?” He asked as he turned around and hid his face in
Reigen’s neck as he fisted his collar in his small hands. Reigen held in a
groan when he looked down Mob’s back to his ass – one of his most favorite
sights in the world. Now that he was this close, however, it was impossible for
him to keep his hands off it.
Mob gasped when he felt his Master push his fingers up under his shorts to grab
his ass as best as he could. The boy gasped and froze in his arms, before
letting out a whine himself and pushing back into his hands. Disbelief was
plain on Reigen’s face, but it was gone in the next instant as he turned his
face to press his lips to Mob’s ear, a sly smile on his lips.
“You’re going to have to help Brutus expel the spirit from his own body.”
Reigen said, sliding his fingers out and dragging his hands up Mob’s ass to the
top of his pants. “And to do that, he’s gonna need yours to help him out. You
want to help him, right?”
Mob nodded into his shoulder and shivered once again.
“Good boy.” Reigen said as he brought his hands to the front of Mob’s pants in
search for his button – he was sidetracked immediately however, when he brushed
against the boy’s small dick straining against his pants. Mob gasped and
lurched in his arms.
“Well well…” Reigen said as he palmed it easily. Mob’s eyes flew open and he
arched his back, thrusting his ass back into Brutus’s eager snout. The dog
forced his nose between Mob’s legs and further with vigor, and he lapped
eagerly at the boy who shuddered and shook and spread his legs further. “Looks
like you are willing to help.”
“Please, Shishou…” Mob gasped, fingers tight in his shirt. Blood smeared over
his lips and down to his chin, and Reigen was sure some was soaked into his
collar.
“That’s the spirit, Mob.” He praised as he unbuttoned Mob’s pants and pushed
them down his thighs. His underwear went right with it, and in moments Mob’s
cock bobbed in the cool air and he cried out as Brutus’s tongue slid over every
inch of skin he could reach.
“I won’t let him hurt you during this.” Reigen said as he dragged his hands
back up to hold Mob’s ass. He spread his cheeks apart and watched as the dog
lapped at his asshole like it was covered in cream – that image alone derailed
Reigen’s train of thought for a solid minute. “So that means I have to finger
you a little bit. Are you alright with that?”
Mob looked at him with hazy eyes, and his mouth was open and wet. When he
nodded with a shudder, and opened his legs further to the wet pressure of the
dog’s mouth, Reigen smiled and reached down to slide a finger across his slick
hole easily.
“Aah!” Mob cried, squeezing his fingers tight as his eyes blew open. “S-
Shishou!”
“It’s alright Mob, I’ve got you.” Reigen said as he rubbed his finger in
circles around Mob’s entrance. To help sweeten the deal, he slid his other hand
down and took a loose hold of his dick. Precum and saliva had already lubed it
up enough for his hand to slide across it easily.
Mob choked on his spit and jerked in his arms, and Reigen praised him gently as
he began to work his finger in. Mob lolled his head against his shoulder and
whimpered as he moved with the motions of Reigen’s hand, and he gave his little
dick a good squeeze at the head. The boy groaned and rocked his hips, back onto
Reigen’s finger and forward into his palm.
Before long, Reigen had stuffed three fingers in Mob’s ass, and the boy was a
wet mess against his chest. The irritated skin on his lip had split even
further, and when Reigen looked down to push Mob’s sweaty bangs off his face to
take a look at him, he saw his shirt was damp with sweat, tears, and
bloodstains. He let go of Mob’s hair to reach down and palm himself through his
pants for a moment.
“I think we’re ready.” He said, pulling his fingers out slowly. Mob’s arms
folded in and he collapsed against his chest. A ragged, slow breath warmed
Reigen’s already heated skin through his shirt.
Carefully, Reigen helped Mob position himself on the ground, hands and knees in
the soft moss, legs apart, tiny cock and balls hanging between his thighs.
Brutus let out an excited whine and dug his back legs into the dirt trying to
reach Mob from his position tethered only two feet away from the boy.
Reigen stood up and ran a hand through his hair and stood a moment to
appreciate the sight before him. Mob was looking up at him with glassy, dark
eyes, with pupils that seemed large enough to get lost in. When Reigen held his
gaze for a moment, the boy turned his head as a pink tint reached his cheeks.
“Shishou…” He said, kneading at the ground anxiously. “Don’t… Make me wait…”
Reigen huffed out a laugh and decided now was a good a time as any, and walked
around Mob’s body to the dog. Brutus looked up at him and back down at Mob,
drooly and excited and still so hard. With a pop, he unhooked his collar from
the leash, and the dog surged forward.
Brutus was quick to help himself up onto Mob’s back, and his dick fit perfectly
between Mob’s slick ass cheeks. Reigen had to admire the scene from the back
for a second – Mob’s pale skin looked nearly white under the dark coat of the
dog, and the dog’s dick was bright red between the two of them.
After a few sloppy movements, Brutus finally managed to line the head of his
dick up with Mob’s entrance, and he jerked his hips forward hard. Reigen
watched it slide in easily.
Beneath Brutus, Mob gasped. His arms shook under the weight of the dog on top
of him as well as in response to the stretch he was feeling; Reigen moved back
around to Mob and pet through his hair comfortingly.
“That’s it, Mob, you’re doing great.” He murmured, moving one hand down to his
own pants to undo his belt. Mob was groaning and drooling and trying his best
to stay upright, but Brutus was really making it hard on him. The dog fucked
him mercilessly, with all the power he had. He was frothing at the mouth with
all the energy he was putting into it, and panting nearly loud enough to drown
out Mob’s own noises.
The sound of the dog’s balls hitting Mob’s skin repeatedly helped speed
Reigen’s efforts up to drag down his own zipper and pull himself out. He was
hard and leaking, and after he spat in his hand and stroked himself a few times
as he knelt in front of his student, he hazily wondered why he hadn’t thought
to do something like this sooner.
“S-Shishou!” Mob gasped when Brutus found an especially sweet spot in his body.
The boy arched his back and looked up at him with large and wet eyes, his mouth
open, needy, greedy, but so sweet and young. For a second, Reigen wondered if
Mob knew just what kind of effect he’s had over him since he first walked in
through his door. He had been so young – hell, he was still so young.
I wonder if he’s started masturbating yet Reigen thought, gripping himself
tight at the base and reaching out to grab a handful of Mob’s hair so he could
force his head up, just so he could keep looking at his sweet expressions. The
boy whined and let his tongue push past his bottom lip. Reigen felt himself
twitch.
“Shishou, it’s so big…” He said. Mob’s eyebrows were knit together and his
bloody lip looked much too inviting for its own good; Reigen let go of his hair
to hold Mob by his chin to allow himself the pleasure of rubbing his thumb over
the raw flesh. Mob shuddered and looked up at him as he slid his tongue out
once more to try and stifle the pain of his lip.
“Mob, do you want to help me, too?” Reigen asked, looking past Mob’s face to
watch as his body rocked under the dog. Red marks blossomed over his back where
he had accidentally scratched him with his paws in trying to maintain a good
position on the small boy’s back.
The boy nodded his head. Reigen breathed out slowly through his nose, willing
himself to keep it together for at least another minute – at least long enough
to slide his dick past Mob’s red lips. He withdrew his hand from Mob’s mouth
and replaced it with the tip of his dick, which he let rest just inside his
line of white teeth.
Mob fumbled with his tongue around his head. Brutus was obviously not helping
the poor boy, what with the constant thrusting that forced Mob’s head on and
off his dick in frantic, quick bursts. Reigen hissed when his teeth grazed his
head a little too firmly, but he laid his hand on the back of Mob’s head
lightly and scratched at the short hairs there to comfort him.
“That’s it, Mob, you’re doing great…” He praised as he pressed his hips
forward. His dick slid between Mob’s tight, wet lips, and the feeling of his
small, tentative tongue sliding against him like Mob enjoyed the taste of his
dick pushed him further in.
Mob panicked for a moment as Reigen slowly pressed in further, until he was
halfway in. He gagged, hard, and Reigen pulled back for a moment.
“No no!” Mob said, struggling to reach forward and get it back in his mouth. “I
want it back! I want more!”
Well… Reigen wasn’t going to argue with that.
Just as he slid his dick back between Mob’s lips, Brutus pressed forward hard
enough to bury his knot deep in Mob’s ass. The boy gasped around his cock,
which pushed past his tongue to the back of his throat. Reigen swore and pulled
his dick out, but it was too late, and Mob puked over his dick and the cool,
dewy moss.
“I – I’m sorry Shishou!” Mob gasped, his mouth still wet with vomit that slid
down his chin and to his neck. He was about to say something else when he
shifted to wipe at his mouth with the back of his hand, but the motion of
shifting his weight brought Brutus’s knot back into light, and he whined as he
arched his back to feel it pulse inside him further.
As for Reigen, he hardly heard anything out of Mob’s mouth – he was much too
busy looking at it. Mob’s puke was pink from all the blood he’d swallowed, and
that alone was nearly enough to bring him over the edge.
Reigen was nothing if not a fighter, however. Gripping his dick in one hand and
Mob’s hair in the other, he brought himself to release with a few quick, sloppy
strokes, and in moments he added to the mess on Mob’s tongue. The boy groaned
and swallowed the stripe of cum that streaked across his tongue, and Reigen
watched that through unfocused eyes. At the same time, Brutus pulled his dick
out and lapped at the mess that leaked from Mob’s ass for a moment, before
falling to his side with a content yawn.
Finally, Reigen had gathered his wits about him enough to remember that Mob was
the only one present who hadn't gotten off. Spitting into his hand, he reached
beneath his slim body and gripped his small cock. Mob's arms collapsed under
him, and the boy was off in his hand like a rocket in just the same amount of
strokes as he needed eariler. 
After a dazed moment shared between the two, both Mob and Reigen passed out in
the now silent clearing. Soon, all three of them were asleep.
 
===============================================================================
 
Hovering twenty feet above them, the spirit that had been plaguing the kennel
swore profusely. It was just his luck that some idiot man would stumble in and
preform such a sacrifice here. Grumbling to himself, he folded his arms over
his chest and left the area to find a new haunt. 
End Notes
     I like to think Reigen adopts Brutus after this.
Please drop_by_the_archive_and_comment to let the author know if you enjoyed
their work!