A/N:
So basically, Kei's mad that his cat has been getting friendly with one of their newly moved in neighbours, so he decides to teach his kitten a lesson.
Edit: cat is not used as a desciptor for a pet lmao, I basically just made Yama into a catboy y'all.

_____

"Com'on, Yamaguchi", his voice was the same bored, dry tone it had always been, had Tadashi not know Kei, but there was something more, like a feeling burred deep under the commanding words.
Tadashi could confirm that he was quite literally shacking in his shoes, tail swishing from one side to the other in rapid movements. He was honestly quite scared.he didn't even know why, after all, Kei wouldn't hurt him.
Right...?

But Tadashi also knew that his master had told him multiple times to always tell him if he wanted to go somewhere and had even warned Tadashi not to get to close to their new neighbour, a hyper-active red head, that went by the name of Hinata Shoyou.
The thing is, Hinata was such a lighthearted and funny person, Tadashi couldn't help but try and hang out with him more. Don't get him wrong, he loved Kei with all his might, but their neighborhood was pretty boring, so one couldn't blame Tadashi for wanting new friends.
But he had done something wrong. He had let Hinata pet him. Now, for any other Neko, that wouldn't be too big of a deal, but Kei tended to get... Possessive sometimes...
Well, it's not a big deal, most of the times, but...

He knew he was in trouble the moment he noticed the tall blond leaning into the doorway, golden eyes cold and arms crossed over his chest.
"Yamaguchi", he spoke in a deliberately monotone voice, but there was an icy edge to it. And of course he wouldn't use his first name, not when he was angry.
He and Hinata had just been watching a movie, but Tadashi has fallen asleep and Hinata thought that there was nothing weird with some petting. That's where he was wrong.
Tadashi threw a look at the red head over his shoulder and gave a tiny smile as he waved bye.
Tadashi gulped as he and Kei walked the short distance to their own house.
"T-tsukki...?", he sounded the same way he felt, small and worried.
"We will talk inside."
With a heavy sigh, Tadashi's eyes widened as he nervously waited for the blond to open the front door.

Once inside, Kei pinned him into the door, after closing it behind them.
"Tsukki-"
"I told you not to leave without my knowledge, did I not?", his words were like tiny shards of glass, but his voice was low and dark, like honey in a way, dripping.
"I-I know, but-"
A hand slammed itself right next to Tadashi's head, one of his ears flinching heavily.
"But what."
Kei's other hand went to grip the Neko's waist in an almost bruising way. "But what, Tadashi?"
The Neko let out a small whimper and Kei's eyes softened just a little.

After all, was it not natural to be angry? It was for Tadashi's own good, all the rules Kei made. Nothing more and nothing less.
If he knew where Tadashi was, then the chances of anything happening to his precious Kitten were small, almost inexistent.
"I-I really l-like... Hanging out with H-Hinata...", Tadashi whispered, head leaning into Kei's shoulder. His breath was a little bit faster than it should have been, but Kei was so close...
As for Kei himself, he felt a strange pang of jealousy run through his body, blood boiling. Let it be made completely clear, Kei knew Tadashi needed other people... Friends, in his life too, but that didn't mean that he had to like it.
Long fingers went from a sharp hip behind a quivering ear. He scratched for a little bit, before gripping dark brown hair between those same long fingers.
An almost silent whimper left Tadashi's mouth, eyes closing at the little bits if pain. But it wasn't... Bad, somehow. It hurt but...
Tadashi opened his eyes again and deep green met molten gold. Kei's face was dark with a feeling the Neko wasn't aware of.
"Tsukki...?"
At that, the man swooped down and took a thigh in each hand, holding the Neko close to him and supporting his weight with two palms glued to Tadashi's butt.
"Eeeeh?!", A meek squeal and Tadashi was holding on for dear life as Kei brought them upstairs and threw the Neko on their oversized bed (after all, Kei was already too tall to fit in a normal bed, but Tadashi, for a cat, was pretty tall himself).
"Tadashi", Kei said, voice deep and dark.
Tadashi watched as the tall blond made his way towards him on the bed, a predatory shimmer in the barely- there smirk he was sporting.
"Call me Kei."
As soon as those words were said, Kei basically jumped Tadashi, hands gripping his things and pushing them open to settle himself between them.
Tadashi let out a hot gasp, which only made the fire raging through Kei's body burn brighter.
"K-Kei, wha-", he tried, but didn't get to finish, as Kei slammed his lips on to the other's. A cry was ripped from the Neko's throat as he felt that mouth devour his own.
Kei took the opportunity and invaded the other's mouth with his tongue, moving slowly but with a passion that burnt hot into every movement, every lick.
Tadashi circled his arms around his Master's neck, legs trying to shut, but not being able to, due to the blond sitting there.
One of Kei's hands started moving, soft fingers going from his freckled hip bone to his back, caressing the long, tightly tensed tail.
Yamaguchi mewled at that. Kei knew his tail was a very sensitive spot, so why was he moving his hand along the soft fur so agressivelly?
Kei just puffed out a breath and started peeling Tadashi's clothes off for him. Tadashi was just keening, eyes closed and mouth wide open as he ket out those heavenly noises that went straight to Kei's cock. He was already hard as it was, but Tadashi was just so... Enticing.
"K-Kei... Please...!", Tadashi shivered on the bed, trying to catch his breath, action deemed impossible by his brain.
Kei went on and attached his mouth to the now bare neck presented to him.
He started with soft kisses on the long and spotted collum of the Neko's throat. Then the kisses turned into sucks and licks, and then came the biting.
Between all of this, Kei managed to say these words in a dark tone:
"No, Tadashi..."
A surprised gasp-turned-moan-at-last-second rolled off of Tadashi's tongue.
"Tsu-... Kei...?"
"Tonight, we're playing by my rules."

Tadashi moaned loudly as he was roughly pushed face first into the bed and 'omph'-ed as his ass was raised high into the air.
Kei was behind him almost instantly, big palms pressed onto firm and round cheeks
"You...", Kei said as he stuck three fingers into Tadashi's mouth, moving them around to get them coated with his saliva.
"... Have been such a bad little boy..."
Tadashi let out a confused (and mufled by the fingers currently squeezing his tongue between three finger pads) breath.
"But do you know what naughty boys like you deserve...?"
Tadashi swallowed around Kei's fingers and his tail flicked. He felt lust flow through his body, mixing in with fear and a little bit of guilt.
"Boys like you have to get punished...", Kei mumbled, burying his face into the Neko's neck, imhaling deeply. He closed his eyes, enjoying the sounds his kitten was making, when he felt the smaller one's tail brush against his leg.
In a swift motion, Kei grabbed it with his free hand and ran his hand down the silky fur covering the tail.
"A-AH!", Tadashi nearly screamed at the stimulation and in that moment, Kei finally took his fingers out of Tadashi's mouth and ran the wet pads over the Neko's entrance.
"T-Tsukki, wait...!", Tadashi tried desperately, wiggling his butt even more, unknowingly turning Kei on even more than before.
The Neko mewled as two fingers began caressing his walls roughly.
"No, Tadashi. Tonight, I'm going to take you hard tonight. Do you know how much you've upset your Master?", Kei whispered in a dark voice, licking the side of Tadashi's neck slowly, biting into the freckled skin hard enough to draw blood afterwards.
"Tsukki, I-"
"Now, now, you aren't allowed to call me that, you slut."
A full body shiver went through Tadashi's body at that, the fingers inside him moving faster than before, a squelching sound accompanying every thrust.
"M-master...! P-please, I- ah!- I want you i-inside..."
Kei chuckled lowly, and bent a bit down, plunging in another two fingers, scissoring the four appendages into his kitten, knowing full well that he wasn't hitting the smaller's prostate. He smirked as Tadashi trembled, letting out small puffs of air and sharp gasps.
"Now take me like the cock-hungry whore I know you are~"
With that, Kei finally took his fingers out and slammed his dick into the Neko roughly, spreading his palms over his ass.
"AH~!"
Tadashi let out a half yell, ears flattening onto the sides of his had and tail twitching violently.
"Yeah, just like that, baby. Taking me so good...", Kei mumbled as Tadashi's wet heat squeezed around his member. He started thrusting in and out at a moderate pace, hands finding Tadashi's hips and gripping in a bruising way.
"M-Master...!"
"Hmmm~?"
Tadashi turned his head slightly to watch Kei, his beautiful green eyes filled with tears and his lip quivering, a string of saliva falling down his chin.
The Neko mewled loudly before continuing:
"Please f-fuck e harder, Master~"
At that, something snapped inside Kei and all of his feelings of jealousy bubbled up, making him start pound into the Neko ruthlessly, as if he was trying to break the poor kitten with his cock. And in a way, he was...

Tadashi moaned loudly in a high pitched voice as his Master moved I inside him at an almost punishing speed.
It hurt a bit, in all honesty, but Tadashi couldn't help but be reduced to a moaning and keening mess.
His upper body collapsed, ass held only by Kei.
The pleasure was almost biding and with the little bit if pain, Tadashi was walking in the edge, ready to fall into a pit of ecstasy.
"Master,I-I'm gonna c-cu-"
"Ah so you would cum only from my cock? What a slutty kitten I have...", He mumbled between harsh breaths, his pounding increasing even more.
Tadashi was screaming at this point, clawing up at the sheets. It was too much, too much...! He was so close!
Kei got closer to Tadashi's ear and whispered darkly:
"Cum for me, my slutty, little kitten~"
At that, Tadashi opened his mouth in silent euphoria, his whole body coming apart and drifting back together at the force of his orgasm.
All strength left him as Kei kept fucking into him like there was no tomorrow, nailing the spot that made Tadashi see stars.
As Kei got faster and started thrusting deeper, putting more force into every roll of his hips, Tadashi couldn't help but get close to another orgasm.
Soon, Kei's body stuttered and Tadashi felt warm cum fill him up. That coupled with the over stimulation made Tadashi come a second time.
This time, both of them collapsed on to the bed, Kei gathering his kitten up in his arms and petting him lightly, whispering words of love after such an intense round of sex.

~°~

"You know you're mine and I love you, right, kitten?"
Tadashi flashed his Master a tired, yet loving smile.
"I love you too, Kei!!"