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Love.
It’s the age-old question. What is love?
A whole load of bullshit is what it is, in Katsuki’s opinion.
He huffs, wriggling around to try and get more comfortable. The omega on his chest whines at being temporarily dislodged, using strong thighs and arms to wrap himself around Katsuki like a goddamn koala.
“Jesus, nerd. Your mom got the heating on max or somethin’?”
Izuku doesn’t answer in words. He just snuggles impossibly closer, his soft breath ghosting Katsuki’s neck. A droplet of sweat drips down his brow as he sighs, allowing the omega to do as he pleases.
Love is lying in bed with your snot-nosed best friend sweating all over you and knowing that’s as far as it’ll ever go.
In other words, bullshit.
Yet Katsuki wouldn’t change it for the world.
After all, how long does he have left to do this with Izuku before an alpha comes along who can do it better? Who can give him what he really needs? The type of pheromones that’ll make him dizzy and pliant, the type of body parts that’ll leave him full and panting, satiated on a knot-
He pushes that thought to the side as soon as it appears, chest constricting tightly.
“Hey, Katchan…?”
He looks down to the freckled face pillowed on his chest, green eyes half lidded and curious. “Something wrong?” Izuku asks, voice a breathy murmur.
“No, why?”
Izuku doesn’t look convinced, yet he doesn’t look like he can do much about it either. He swallows thickly, fingers clutching Katsuki’s shirt tightly. His eyes are watery, the earlier flush of his rosy cheeks travelling all the way down his neck. The heat must be hitting him hard.
He should tell him. He should say how bullshit it is that he’s a beta. That he can’t give Izuku what he needs. That he can’t make the nerd his forever.
He doesn’t.
“I said no, what is it?”
Izuku doesn’t answer right away. Instead he closes his eyes in a tight clench, face digging lower until he’s burrowing into Katsuki’s side. He thinks that he must be having a bad cramp, concern clawing its way up his throat at the thought of his omega in pain.
Then Izuku opens his mouth, words a heavy gasp, “You smell really strong, Katchan.”
That’s all the warning he gets before the little shit is pushing his face into his armpit. He flails, trying to grip the wriggly fucker, but it’s too late. Izuku’s already digging his nose in and sniffing.
“Hey! What the hell has gotten into you?!”
It’s like his words have no effect on the omega. He just sighs and burrows deeper, his plush mouth grazing sensitive skin. It sends a shiver through Katsuki’s whole body, right down to his damn crotch.
“What do you think you’re fucking doing?!” He spits, heart hammering in his chest because what the fuck? Why does it feel good? “Get off!”
All those years of empty threats and half hearted grumbling must have rendered Izuku immune to his anger, because the omega only slots a leg between his own, dragging himself closer.
“Seriously!” he says, trying hard not to let the nervous panic he’s starting to feel show in his voice. “What’s your damn problem?!”
Because all of this shit… It’s doing something to Katsuki. It’s making him feel things . Weird, strange things, like- like a pressure in his chest, rising through his throat and making him want to growl . Like encouraging the sweet omega on top of him to do it more, to take whatever he needs.
Oh, and it’s making his cock rock fucking solid, too.
“Katchan,” Izuku sighs against his skin, opening up that pretty plush mouth again to lick him, a wet trail of spit dripping down his armpit. “You smell so good right now.”
“W-what?”
Oh god. He wants to say something to make Izuku see sense. Maybe how they’re best friends and this is crossing the already blurred as fuck line they’ve drawn in the sand. Maybe that their fucking mom’s are downstairs, sipping tea together. But he can’t think. Everything is going hazy, and he’s so hot, and fuck, his cock is so goddamn hard that he might just die.
“Mmm,” Izuku moans, like he’s licking a goddamn ice cream and not Katsuki’s sweaty armpit. “Well, more than usual…”
“Dek-” he says, biting back a gasp as Izuku attacks him again with a wet flat tongue. His curls are sticking to his forehead, lips wet with spit. He looks as dazed as Katsuki feels, hips moving to slot closer to Katsuki’s middle-
“Izuku!” He whines, a clothed cock sliding against his own in short, jerky movements. It’s a little like heaven. It’s a lot like hell. It’s all like fucking fire, spreading right down to his crotch and up around his body, lighting up every single nerve.
“Stop it…” he says, but it’s soft, nothing behind it. This should be weird. Izuku is licking his goddamn armpit. It should be fucking disgusting, but it’s not. The omega’s pleased scent is swirling in his nose, morning dew on an autumn morning, the smell of pine on a mountain trail-
Something else beneath it all. Something as sweet as bubbling marshmallows over a crackling campfire, warm and tempting and tasty.
“This is… weird,” he slurs, control beginning to slip away. His own hips begin to press back, meeting each one of Izuku’s needy humps. The omega gasps against his skin, a sliver of a whine entwined in it. “You’re starting to smell like something too.”
Rational sense floats away, being replaced with something else. Something possessive and ferocious, something that wants to take, take, take and leave nothing left. His chest reverberates around a growl, fangs digging against his bottom lip to the sound of Izuku responding with a wet little whimper.
Wait. Fangs?
Izuku rolls his hips again, this time a hint of wet warmth seeping through Katsuki’s pants to touch his crotch, and suddenly any remaining worries of fangs or friends or we shouldn’t, we really really shouldn’t fly out the window.
“Izuku,” he growls, gripping the omega’s hips to press their cocks closer. “Omega.”
“Katchan-” Izuku whines, pupils blown out, barely a sliver of green iris left as he bats thick pretty lashes. “More.”
His arms move on their own. He knows what Izuku needs. What he was seeking beneath his arm. What he can get more of if he just goes a little lower. He pushes the omega by his shoulders until he’s shuffling down, a hand slipping beneath his waistband to rip his pants off his legs. He hisses as his cock springs free, bobbing angrily, a string of precome already leaking from the tip. It looks even bigger than before, but maybe that’s just Izuku’s cute face beside it, the omega’s eyes glazing over as his nose twitches, assaulted by the scent of him. He twists his fingers in green curls, pulling him forward none too gently.
“This what you need, omega?”
A flicker of awareness seems to light up Izuku’s eyes at the forceful treatment. But then his nose is being pushed into the musky hair at the base of Katsuki’s cock, those same eyes going lax as the omega moans again. He digs his face into Katsuki’s inner thigh, greedily gulping in salty sweat and pheromones. He lathes his tongue there, gasping and groaning, rutting his little cock against Katsuki’s leg like a wild animal. He’s getting what he needs: the full, unadulterated scent of Katsuki.
It’s a fucking sight to see.
His cock throbs, eager and wanting as Izuku laps a tongue over his balls, becoming more scent drunk with each pass. He’s dazed and drooling, whining and mewling. Katsuki grips him hard by the hair, and it’s all instinct that has him dragging the omega to the tip of his cock. Izuku blinks in confusion before setting his sights on his new goal. He sticks out his tongue without prompting, giving Katsuki’s cock a sweet little kitten lick along the slit.
They both groan, loud.
He digs a thumb into Izuku’s wet mouth, petting along his tongue. The omega drops his mouth open obediently, tongue lolling out as he allows Katsuki to do as he pleases.
“Ka’han,” he tries to say, eyes wide and pleading. Katsuki feels along the inside of his cheek, hooking his thumb there and pulling his mouth wide on pure instinct. Izuku lets him, patiently waiting as Katsuki pushes his hips up, slotting his cock into a warm wet mouth.
“Nghh,” Izuku moans, a spurt of salty precome spilling on his tongue. Katsuki pulls him further onto his cock, his own inexperience making him push his hips up too far and too fast, the omega sputtering around the intrusion.
“There we go,” he hears himself say, voice so deep it sounds unrecognisable. “You can take it, omega.”
Fuck. Why is he talking like that? Why is he saying those things-
He doesn’t have time to focus on his moment of clarity because Izuku bobs his head obediently, choking against the tip that’s squished against the back of his throat. Tears spill from the corners of his eyes, the scent of his slick heightening, and then the omega is frantically fumbling his own pants down.
“Taste sho good-” he mumbles around Katsuki’s cockhead before he suckles it into his mouth again, scarred fingers skirting down, passing over his own small cock to settle somewhere further behind.
Inside of himself.
Katsuki growls at the wet slick sound of it, at the sight of Izuku trying to swallow cock while haphazardly fingering himself. He feels so warm around Katsuki, so soft and wet and eager. His cock itches at the base, hips pushing up until Izuku is gagging and drooling more spit.
It’s so fucking good, yet something’s wrong. Jealousy rises in his chest, because Izuku is touching something that belongs to Katsuki.
His warm wet omega hole.
With a snarl he pulls Izuku off his cock, dragging him up only to push him down on his back. He looms over him, the omega’s wrists trapped within his palms, wide eyes staring up at him.
Izuku’s fingers shine with slick.
Katsuki snarls again.
“That belongs to me.”
He gets a distressed whine in return, Izuku squirming beneath him, scent placating- and then the omega tilts his head back, baring his neck as fat tears drip from his eyes, lower lip wobbling.
“K-Katchan-”
“It’s alright,” Katsuki rumbles, some roaring thing in his chest filled with glee at the omega’s submission. He ruts his heavy cock against Izuku’s smaller one like it’s a reward. “So good, aren’t you? My good little omega.”
Izuku makes a sound of pure delight and ruts back. They press up against each other in slick slides, haphazardly grinding until they’re both panting into each other’s mouths. They inch closer and closer, mouths brushing, until finally their lips slot together.
Izuku’s mouth is as soft and sweet as the rest of him. Katsuki can taste the warm heady arousal of himself on the omega’s tongue, Izuku’s whimpers like music to his ears. He shifts his hips, cock slipping down between slick wet cheeks.
He chokes back a gasp at how soaked Izuku is. Slick coats his cock as he drags it between supple skin, his cockhead sensitive and drooling. He humps along the seam of Izuku’s ass, happy to get lost in that sensation alone until his cock catches on something else.
He slides right by it, shifting to catch his cock on it again. So small and tight, a little omega hole twitching and begging for more.
“Katchan,” Izuku breaths, green eyes wide and searching, “What- What are you doing?”
He lets go of a wrist and interlinks their fingers, leaning down to press a kiss to his forehead. Making the decision feels as easy as breathing.
“Making you mine.”
He pushes forward.
It’s tight. Tight and warm and wet, welcoming him bit by bit. He drops his head to Izuku’s shoulder, groaning against his burning skin.
“Ahh-” Izuku whimpers, “Katchan, I can’t- It’s too much, I can’t-”
Yet he lifts his hips, letting Katsuki slide in another few inches. His insides welcome him in a warm wet grip, beckoning him deeper.
“You can,” Katsuki pants against his ear. “Taking me so well already, Zu.”
He presses their lips together again, venom oozing from his fangs and dripping into Izuku’s mouth. It makes the omega groan, going loose and pliant as he licks inside Katsuki’s mouth to seek out every last drop.
“Ngghh,” Izuku whines, boneless. Katsuki wraps a hand beneath his waist, hoisting him up so that he can press even deeper. He can barely breath, huffing breaths as he tries not to just fuck forward as fast and deep as possible. To carve a space inside his little omega, to make his hole permanently mold to the shape of him.
To claim him, body and soul.
His hips meet Izuku’s ass, the omega gasping out a whine. His eyes are wide and shiny, tears spilling down his cheeks.
Katsuki leans down and licks one away. Then he presses their necks together, rubbing Izuku’s scent gland with his own. He pushes his scent out, freshly lit tinder opening into a warm campfire. It engulfs them both in seconds, calm and soothing.
Izuku relaxes in his hold, mewling and sniffling against his hair. “It’s so big, Katchan.”
“I know,” Katsuki coos. “Took all of me, didn’t you? So fucking good. ”
Izuku whines again, legs wrapping around Katsuki’s waist, “More. Please.”
“Whatever you need,” Katsuki says, gripping him tight.
The first thrust has them both groaning, pressed tightly together as Katsuki moves his hips. He fucks him with slow solid thrusts that press Izuku open again and again. Izuku holds him close, moaning each time he bottoms out, small cock jerking between their bodies. He keeps the pace until Izuku is twisting a hand in his hair, pulling hard.
“More,” his little omega growls. “Fill me properly, alpha.”
Not an alpha, he thinks. No, not an alpha at all, he’s a-
Oh.
Oh.
“Please, alpha,” Izuku cries, body pressing down on Katsuki’s cock desperately. “I need… I need your knot.”
Katsuki grips his hips, a growl ripping from his throat. Venom dribbles down his chin as he starts fucking Izuku properly.
“Hnng!” Izuku groans, Katsuki’s hips slapping against his ass with each thrust. He snarls as he holds him in a bruising grip, the omega getting pushed up the bed with the force of his fucking. Izuku’s hole spasms around him, drool spilling down the side of his cheek as he cries out. Katsuki’s teeth itch, drawing blood as sharp fangs dig into his own lower lip.
“Mine,” Katsuki growls. The base of his dick swells and pulses, searching for some sort of reprieve, like an elastic band that’s waiting to snap. He’s never felt anything like it, needs to have Izuku’s hole wrapped tight around it, needs to get it in deep and breed him and fill him full of pups-
“Take it,” he snarls. “Take my cock, omega.”
“Katchan,” Izuku gasps, eyes glassy. He tilts his head back, loud ‘uh uh uh’s’ fucked out of him with every rough trust. The long column of his neck lays exposed, his hand reaching and wrapping around his little cock.
“Make me yours, alpha.”
He drops forward, mouth ghosting Izuku’s neck, thrusting once, twice-
His core unravels, pleasure ripping from the base of his cock at the same time that his teeth sink into freckled skin.
He thinks he hears a shout. He’s not sure. All he knows is the spend spurting from his cock and the knot plugging his pretty omega, keeping them locked together. Izuku writhes and loses himself beneath him, his sweet hole milking Katsuki for all he’s worth, watery spend spurting between their bellies. He can hear his heartbeat in his ears, can feel Izuku’s gasping breaths in his own chest.
They’re fully connected.
Mated.
It fucking amazing.
It feels like ages that they’re laying together like that. Katsuki laps at the swollen bite on Izuku’s neck, some stray piece of information about alpha saliva helping the wound heal bouncing around in his head. He holds him tight, fingers stroking Izuku’s side. The omega purrs in his arms, kissing his temple, his hair. Every few minutes he thinks he’s spent, but then his knot is pulsing again as he gasps into Izuku’s neck, the omega holding him close through another round of milking. Each one leaves him oversenstive and groaning, yet somehow another still gets pulled from him minutes later.
By the end of it he’s boneless, head and heart full of Izuku.
“Katchan?” Izuku murmurs. “Are you okay?”
“Shouldn’t I be asking you that?” Katsuki says. He leaves one last gentle kiss on Izuku’s fresh bite, pulling back to look at him.
Izuku looks… well, he looks like he’s been thoroughly and utterly fucked. His green curls stick to his skin, a lovely flush colouring his cheeks. His eyes are soft and sleepy, eyelashes fluttering against his cheeks each time he has a heavy blink. The shape of teeth mark his neck, placed in a perfect crescent moon.
But suddenly his omega doesn’t look happy, eyebrows knitting and lips curling at the edges.
“Are you sure about…” Izuku says, eyes drifting to the side. Katsuki can tell that the heat is clearing for him, that he’s coming back to himself again. “Are you sure that you want this? Because if you don’t, if it was just a spur of the moment thing, I’ll totally get it, I mean, we don’t have to- just because we- you don’t have to-”
His scent is getting all muddled, distress and anxiety peeking through when he should be calm and relaxed, completely satiated on a knot. Katsuki growls softly, tilting Izuku’s chin until those big green eyes are looking up at him again.
“I want this,” he says. “Fuck, I’ve been wanting this. For a long time. I know I fucked up here, that I should’ve fucking courted you first or whatever. But this whole alpha thing has kind of sprung up on me out of nowhere.” He blinks, realisation dawning again, “Shit, I’m a fucking alpha. What the fuck?”
“You want this?” Izuku repeats, ignoring the rest of it. “For the rest of our lives?” he adds quietly.
“For the rest of our lives,” Katsuki agrees. The responding smile that takes hold of Izuku’s lips is blinding.
Their lips meet, soft and sweet. Jesus, Katsuki thinks.
This… this must be what love is.
“I’m still going to court you, nerd,” he mumbles between kisses. “Take you on the best fucking dates you’ve ever had.”
Izuku giggles, “I know you will, Katchan.”
This is pretty perfect, Katsuki thinks. He lays his head on Izuku’s shoulder, knot finally beginning to shrink, and damn, isn’t that a strange new feeling? His eyes go half lidded, the scent of pine and morning dew all around him, sleep tugging at the corners of his vision. He thinks he could lay here forever, for the rest of his goddamn life, if Izuku let him-
“Boys! Didn’t you hear me? Dinner’s ready!”
That’s all the warning they get before Izuku’s door is swinging open, his mom and Inko on the other side of it. They don’t even get the chance to cover themselves with a blanket, the naked evidence of what’s just occurred on full display, right up to Izuku’s pretty bitten neck.
“Oh my god,” his own mother says with a surprised smile. “You’ve finally done something right, Katsuki! Isn’t this amazing, Inko?”
And, well. They don't get an answer for that one, because Inko passes out.