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Shouto grunts quietly as Katsuki’s tight cunt squeezes his cock. He’ll never get tired of this. All his frustrations of a poor day, all his anger at his fucking awful father, all his quiet sadness at the state of the world fade away when he gets his cock wet with his Katuski’s beautiful body.
He’s grudgingly willing to admit if his piss poor father has made one decision right it was to get him a slave. He doesn’t have the time to go find a suitable mate or worry about proper etiquette while courting and more importantly fucking them. With Katsuki, he can just do what he wants.
“Don’t be lazy, Katsuki, pull those nipples,” he commands, letting his thrall slip into his voice so Katsuki has no choice but to obey him. Someday Katsuki will listen on his own but Shouto doesn’t have any qualms about using his thrall till then.
It’s a gorgeous sight, Katsuki splayed open before him, eyes wet with tears, lips bit to keep his moans quiet, and pinching his own nipples till they’re pained red.
Shouto thrusts harder, uncaring about how Katsuki takes it, he knows his slut likes the pain. He doesn’t know if he came like that or if Shouto trained him into it but does that matter?
Pleasure thrums through his body as his knot becomes increasingly hard to pull out. He lets out a low groan as on the next thrust it refuses to come out. He loves filling Katsuki up.
“Wait, wait,” Katsuki cries out. Shouto opens his eyes, annoyed, did he forget to command the bitch to be quiet?
“Please master,” Katsuki whimpers, “I don’t want to be pregnant!”
Oh. Shouto didn’t realize he was already cumming. Now he’s even more annoyed. Why did Katsuki ruin his orgasm?
He can see the second Katsuki realizes what he’s done because his pussy squeezes him apologetically. Huh. He’s surprised he’s not mad. He guesses he almost misses when Katsuki was loud and brash and fought with him.
That has to be the only explanation for why he’s not beating Katsuki up right now. Or…it’s more likely that he can now think of a delicious punishment. What use will anger do? That’s something his father never learned.
“I’ll get you the potion tomorrow if you’re good for me, mutt,” he says with a cruel smile. With his alpha genes, there’s no way Katsuki won’t get pregnant. Only the potion can stop it.
Katsuki closes his eyes in defeat, probably trying to calm himself. He always did struggle with being good.
Shouto leaves Katsuki, pussy dripping with cum and slick, so he can think about how he can use this.
He allows a smile as he approaches Katsuki’s chambers. He’ll admit he’s excited to see what Katsuki has planned.
Shouto knocks to announce his presence. It’s to give Katsuki a chance to always greet him properly. He’s not one of the maids or servants that Katsuki can gripe around. His omega should always be ready for him; he’s gracious enough to give him a few seconds to prepare.
The heavy door opens to Katsuki sitting demurely at the edge of his bed, dressed in a black frilly skirt. It doesn’t even cover his pussy, just the way Shouto likes. His nipples are clamped with little bells that jingle as Katsuki fidgets nervously.
Shouto smirks. It’s a good start. He gives Katsuki a nod and the slave scrambles to get on the bed, knees bent, face down, ass up. He circles his hips and the shimmery edges of the skirt flounce around his gaping pussy.
Shouto unlaces his trousers as he walks up to him, simply grabs that dainty waist, and slides his cock right in.
“But -” Katsuki cries.
“I’m not convinced just yet, slut, try harder,” Shouto says.
Katsuki trembles but throws his hips in small circles as he tightens the grip his pussy has on Shouto’s cock. With one wobbly hand, he reaches his jingling nipples and pulls at them even harder than Shouto ever has.
Shouto actually groans in pleasure. Fuck, he loves how Katsuki’s always ready to hurt himself and he never has to worry about breaking him because the stupid mutt gets wet from it. His pussy is leaking all over Shouto’s balls as he hammers in his cock.
But it’s the vision of his cute, round butt dancing for Shouto’s pleasure and wrapped up in those pretty frills like a present that really has Shouto’s attention.
“Hold still,” he mutters and Katsuki freezes under his thrall. It’s going to hurt him but eh, Shouto wants what he wants. Katsuki will be fine.
He yanks his cock out - it's dripping in slick, Katsuki should thank himself for being such a whore - and pushes it into the small, virgin hole in his ass. He’s not awful so he does it slowly, letting Katsuki’s body adjust to the pace he thinks is correct but he definitely isn’t stopping till he’s sheathed inside.
He glances at Katsuki and finds tears dripping down his face. “Beautiful,” he whispers as he reaches forward to wipe one away.
Shouto thinks he’s been patient enough. The vice grip Katsuki’s ass had on him has relaxed just enough that it’s not uncomfortable for him anymore. He grips his waist, pulls his cock out and slams it back in.
“So fucking tight,” he can’t help but moan, “even tighter than your slutty pussy the first time I had it, mutt.”
Katsuki doesn’t respond but Shouto knows his slave must be aware that he’s pleasing him by now.
He rakes his hand down Katsuki’s back, reveling in the lines of red that follow. He doesn’t drink from Katsuki often but right now he allows himself a little taste as he licks the lines clean.
He pounds into that ass hard and deep, almost entirely out of control. He’s not usually one to lose control but it really is so tight, so tight and so hot. He’s a fool for taking so long to do this. Suddenly he realizes he wants to see Katsuki’s face.
It’s hard to pull out with how good it feels but he forces himself to do and quickly flips Katsuki onto his back. He pushes Katsuki’s knees by his head and thrusts in again.
Katsuki is beautiful. Dried tears frame his face, his eyes are rolled back into his head, and he keeps making these sweet little mewls. Shouto grins. He knew Katuski would love this. He loves everything Shouto does to him.
He presses down on Katsuki’s knees as he fucks him and is delighted with how slick drips down to his ass, wetting Shouto’s way in. No one enjoys a dry fuck.
“Hold your legs,” he says in his normal voice and tries to hold back his laugh when despite the nonexistent thrall, Katsuki immediately obeys. He really is a slut.
Now Shouto can really enjoy himself. He sets a punishing, inhuman pace. His balls smack against Katsuki’s taint and his hands pinch those delicious, bruised nipples that have been singing for him this whole time. Maybe he’ll make those bells permanent.
When his knot grows large enough for Katsuki to notice, he starts begging Shouto to stop, saying lies like it’ll destroy him, he can’t take it, his ass will never close again.
Shouto rolls his eyes, he knows better. “I’ll get you the potion,” he says to stop Katsuki’s whining.
Katsuki stops his begging. He grits his teeth, holds his thighs tighter. His pussy keeps dripping.
Shouto continues to bully his ass open, fucking him with his growing knot and when it starts catching on his rim, he decides he wants more.
“I changed my mind,” he says and Katuski stares at him in horror, “don’t be like that, I’ll get you the potion. I’ll get it if you can cum like this.”
Katsuki visibly panics for once but starts weakly thrusting back and moaning fakely. Shouto shakes his head. He knows Katsuki knows he can’t pretend. He could just command Katsuki to cum, his body does belong to Shouto after all, but where’s the fun in that?
“You act as if you don’t want it,” Shouto says, annoyed.
“I - I - I do!” Katsuki says, “I’ll - I’ll prove it.”
He takes one hand off his thigh and Shouto has to appreciate his flexibility because the leg stays in place despite nothing holding it down.
Katsuki slips the free hand down to his cunt and starts rubbing his clit aggressively. The bells jingle loudly.
“Faster,” Shouto says.
Katsuki looks at him, determination flashing in his eyes. He raises his hand and brings it down hard on his open pussy. His ass squeezes Shouto’s cock.
“Fuck. Fuck, that was good, do it again,” Shouto really has to try and keep the thrall out of his voice now. He wants to command Katsuki to beat his pussy but he also knows if he’s just the slightest bit patient, Katsuki will do it anyway.
And he’s right. After that first slap, Katsuki abandons all shame. Loud smacks join his ringing nipples and he moans the way he does when he finally lets go of how much he hates being a slave.
His pussy turns a lovely shade of red and slick flows freely. Shouto is so happy with his mutt that he decides he’ll help.
Between the slaps, he reaches down and twists Katsuki’s clit. The omega yelps but his pussy starts fluttering like it always does when he’s about to cum so Shouto twists even harder.
Katsuki’s tongue rolls out his mouth and his eyes glaze over as his orgasm finally hits. Slick sprays out and his ass clasps Shouto’s cock like it never wants it to leave.
Shouto growls as his knot finally catches, fully formed, and leans down to bite Katsuki’s lolling tongue. He’s rewarded with the smallest trickle of blood.
It heightens his orgasm even more. His vision whitens in the most powerful, most violently wonderful orgasm he’s ever had. It’s good enough to almost make him forgive his father. He stuffs Katsuki full, happy that the omega isn’t whining for once.
When he’s done, he collapses on Katsuki’s soft, pillowy tits. The clamps bite into his cheek but he ignores them. The moment is perfect.
Katsuki breathes heavily below him. He stretches out his legs and lets them fall around Shouto’s waist.
Shouto nips at Katsuki’s throat. He feels so fucking good. It’s time to reward his slave. Staying in place, he thrashes a hand over the bed’s edge to blindly search for his abandoned trousers.
When he finds them, he reaches into the pocket to pull out a small, oblong-shaped vial full of blue liquid.
"Good omega," he tells Katsuki as he pulls down his jaw and pours it down his throat.
Katsuki blinks at him in surprise but swallows dutifully.
Shouto wants to pout. Did Katsuki think he wouldn't keep his word? He's only done that twice or thrice! He doesn't deserve this mistrust.
"There, no more worries about pups," he says sulking. He thought Katsuki would be happier. Truth be told, he really isn't ready to be a father. Maybe never. The doubt comes with having that bastard Enji as a father.
“Th-thank you, master,” Katsuki says with an almost smile.
“This is good,” Shouto says as he settles back down to wait out his knot, “Now we have a place I can cum without you freaking out like a little bitch each time”
“You’ll… you’ll only fuck me there?”
“I’m not cruel, Katsuki. I’ll fuck your needy little pussy and when I’m about to cum, I’ll just switch holes. I like knotting your ass and let’s stop pretending you don’t love this.”
Katsuki whimpers but his ass squeezes lovingly around his knot. Shouto knows he’s right.
When his knot finally goes down, he asks Katsuki to clean them up. He hates that he still has to use his thrall for this. Katsuki just isn’t very domestic, he thinks with a sigh. He’s also not the smartest because he tries to just get off Shouto’s cock.
Shouto holds him in place, picks up the empty vial, and quickly switches his cock with it. Katsuki looks embarrassed but even he has to agree he’ll have less to clean that way.
He lazes in bed as Katsuki cleans them both up and when he’s done, he pulls the omega back into his arms. He wants that vial in all night.
“You wanna warm me while you sleep?” he asks and Katsuki scowls. He knows the omega craves closeness and hates himself for it but well he's not going to do it if Katsuki doesn't ask.
With gritted teeth, he says he does so Shouto settles back into the pillows and lets Katsuki warm his cock as sleep takes them. He’s not sure but as he falls asleep, he thinks he hears Katsuki purring.