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Lately, Katsuki has been getting into a lot of dominance disputes with his alpha mother. It triggers his alpha instincts to claim his rival’s mate. His father is sweet, kind, and caring, and Katsuki is plagued with fantasies of bending him over the kitchen counter and railing him. He knows his mother can’t be giving it to him properly. It would be so easy and it’s exactly what his father needs — a real alpha.
One day, his father is chopping vegetables for dinner and he looks over his shoulder, expression lit up with affection, his scent so warm and inviting, and Katsuki snaps.
He crosses the kitchen before he knows what he’s doing and crowds his father up against the counter.
“Katsuki?” Masaru asks, voice pitched high with worry as his son grinds against his ass. “What — stop!”
But Katsuki isn’t listening. He grabs his father by the scruff of the neck and slams him forward, pins him against the surface of the counter.
Masaru is struggling, but Katsuki is already kicking his legs apart and yanking down his pants. In a matter of seconds, Masaru feels the tip of Katsuki’s cock pressing at his hole.
“Wait! Katsuki, don’t — nnn!” His protest is cut off by a long, drawn out moan as his son’s cock sinks into him.
The worst part is that he’s wet and aching for it. The simple act of being dominated by his son was more than enough to turn him on.
Masaru knows it’s wrong, but Katsuki is much like his mother, very attractive and appealing. He’s a powerful alpha, confident and strong, handsome and smart. Masaru finds himself incredibly slick and eager to take his son’s cock.
He tilts his hips back in silent invitation and Katsuki drives into him, sheathing his big fat alpha cock in one smooth thrust.
Masaru cries out at the sudden fullness, his own aching, tiny omega cock leaking onto the counter.
Katsuki grips Masaru by the hips and starts fucking him in earnest, forcing himself deeper with every powerful thrust. The kitchen echoes with the wet squelching of Katsuki’s cock thrusting in and out of Masaru’s sloppy wet hole.
“Oh, son!” Masaru moans loudly, pitching forward with every thrust. It’s wrong, it’s so wrong but it feels incredible. He’s burning up, throbbing and clenching around Katsuki’s fat cock.
“Fuck, old man!” Katsuki hisses through his teeth. “You’re so goddamn tight! I knew the old hag wasn’t fuckin’ you right.”
Masaru moans embarrassingly loudly at his son’s trash talk. He’s right. Mitsuki’s cock has never felt this good, he’s so hot and full and he wants Katsuki to come inside him. He wants to feel his son knot his ass and fill him with his come until his belly is full with it.
Katsuki is already close, his knot keeps catching on Masaru’s rim, but it’s not swollen enough to lock them in place yet. Masaru whines and grinds back on his son’s cock, desperate to have his knot catch and hold.
“Katsuki, you can do it, baby,” Masaru encourages him and his son makes a keening sound at his father’s praise. “C’mon, keep going, that’s right. Just a little more,” Masaru gasps when Katsuki finally hits the right angle. “Oh, oh yes, Katsuki! Ah, right there! Oh, you’re gonna make daddy come!”
“Ah, ha, fuck! Fuck yeah,” Katsuki growls, nailing Masaru’s prostate over and over. “Shit, how’s it feel to get fucked by a real alpha, huh?!”
“So good!” Masaru moans like a porn star. He feels so hot all over, like he’s going to melt. He’s never been so turned on in his life, he’s so close to the edge, he just needs that last little push…
Katsuki laughs maniacally. “Yeah, bet it feels real good to have a big cock for once. Nngh!” He groans when Masaru suddenly tightens up around him, pulsing and gushing slick. “Oh, fuck,” Katsuki laughs again. “Did you just come?!”
Masaru can only moan weakly, too blissed out to answer.
Katsuki pulls out and a mess of come and slick spills to the floor. He manhandles Masaru so he’s on his back and hikes Masaru’s legs over his shoulders before pressing inside again.
“Fuuuck,” Katsuki drawls. “You’re so fuckin’ wet, daddy!”
They’re face to face now and Katsuki is looking right at him. Masaru is mesmerized by his son’s expression, his handsome face red and sweaty with the effort it’s taking to fuck him, smoldering eyes locked on the way Masaru’s belly bulges with his cock with every thrust.
“Take it, daddy! Take it, take it, take it!” Katsuki chants with every thrust, fingers digging hard enough into Masaru’s hips to bruise. Masaru is gasping, his tiny dick achingly hard again, desperate for his son to finally knot him once and for all.
“That’s it, baby!” Masaru gasps. “Almost — oh, yes!”
Katsuki finally forces his knot through the tight ring of his father’s ass with a vicious snarl.
“Katsuki!” Masaru cries out in ecstasy as he starts to feel his son come inside him. Katsuki’s cock pulses and twitches with wave after wave, emptying heavy loads deep into his ass. Masaru can barely see, his glasses fogged up and falling askew as Katsuki keeps bucking into him, trying to force his come even deeper inside him. Like he’s trying to breed him.
“Oh, son,” Masaru moans weakly, spilling pathetically all over himself when he feels his belly expanding with the sheer amount of Katsuki’s come.
Masaru wishes he could say it was only a fluke, an accident. Something that happened once that they could bury forever, but Katsuki is much like his mother, determined to pursue Masaru regardless of anything or anyone.
Masaru ends up on his back in his marriage bed, sobbing, holding his thighs open so his son can eat his own come out of Masaru’s ass.
Masaru feels like he has no self-control around Katsuki anymore. Whenever they’re alone, they’re fucking like rabbits. On his hands and knees, chest down and ass up as Katsuki mounts him in the genkan, come spilling out around Katsuki’s massive knot to leak all over the floor.
Katsuki fisting him on the couch, powerful arm muscles flexing and his ruby red eyes scorching as he works his fist up Masaru’s ass, slick dribbling down his wrist.
Masaru is humiliated by how much it turns him on, getting fucked by his own son, but he doesn’t stop spreading his legs for Katsuki every time he comes home.