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It's past midnight when Izuku awakes.
He's laying on his side, his rounded stomach comfortably propped against one of those special pregnancy pillows Kacchan had got him. The alpha is still sound asleep behind him, an arm under his neck and another resting against Izuku's hips.
Izuku blinks blearily into the darkness. For once, it's not their pup playing football with his bladder that's woken him up. Rather–
He shoves the covers off of him, rubbing his slicked up thighs together and lightly moaning as his sensitive pussy lips squish against eachother. He's also leaking through his sleep shirt. The thin material is completely soaked through, sticking uncomfortably to the skin of his chest. It's something his doctor had mentioned at his last appointment; that he should expect to start lactating soon but he hadn't anticipated just how horny it would make him.
"Fuck..." Izuku can't hold back the slight hiss as he brings his hands to his wet chest. His breasts feel so heavy to the point of pain. His nipples are swollen, the stiff peaks clearly visible through the now see through fabric, poking through just begging to be milked, to have a warm mouth suckle and knead at it. And he's extra sensitive; a light brush of his fingers over his leaking tits sends jolts of pleasure racing up his spine and he gasps.
"'Zuku?" Katsuki stirs behind him.
The sweet scent of milk mixes with the musk of Izuku's slick, creating a potent concoction that fills the room. It's no wonder that Kacchan woke. His alpha has been extra perceptive as of late; tuned in to every minute change in his pregnant mate's pheromones.
"A-alpha..." Izuku whimpers, cupping his tits and pushing back against Kacchan's groin. His alpha's cock, even when flaccid feels solid and thick through the layers of fabric between them. It has Izuku's already heightened emotions flying into a tizzy. More sticky milk leaks from him.
"Fuck– you're leaking, baby?" Katsuki croons, sleep muddled voice sounding awed when he scents the air and picks up on the sweet, milky scent that wafts from him. Large hands immediately cup Izuku's tits while a thick thigh muscles it's way between his legs. "Leaking from both ends, omega?"
Biting his lip, Izuku nods. Because he is. It's humiliating but also very, very arousing; his pussy clenches out another thick dollop of slick and Izuku squirms.
Katsuki bounces Izuku's tits, feeling their weight and pulling needy little moans from the omega when his rough fingers tweak at those pert nipples.
"Your tits are so heavy, baby. Full of milk for our pup? Such a good omega. My perfect omega. Bred you so fucking good and now you're round and fat and lactating." Katsuki nuzzles into his hair, half delirious on sleep and the entoxicating cocktail of instincts and pheromones enveloping them.
Izuku grinds down harder on the alpha's thigh, his wetness seeping through his flimsy little panties and soaking into the material of Katsuki's sweatpants. He cries out when Katsuki experimentally pinches his nipples a little too hard, sending a delicious wave of pain-pleasure rippling through him and forcing more milk to stain his ruined sleep shirt.
"It hurts so bad, Kacchan. I can't– can't sleep like this." Tears well up in his eyes in frustration, the pregnancy hormones messing with his emotions. He whines, grinding down harder to smush his chubby cunt against his alpha's thigh. He's tired, so tired. But he's also so very aroused. And emotional. His tits are painfully full but his pussy is unbearably empty. He's a confused, horny mess. He's so uncomfortable and he needs–
Relief.
Kacchan shifts again, dragging Izuku with him to arrange their bodies so the alpha is halfway reclining on their plush pillows and Izuku is sitting in his lap, stomach wedged between them.
"Shh, I got you. Want alpha to take care of you, sweetheart?" He slips a hand down between them, shucking off his sweatpants and boxers to free his quickly hardening member. His cock springs out and Izuku inches closer, small hands darting out to move aside his skimpy panties and expose his gushing pussy to the cool open air and guide his alpha's fat cock to his hole. Just the tip. Izuku rocks forward and the blunt cockhead dips inside him, parting his folds around it and smearing pre and slick together.
He tries again, shallowly rocking, watching as Katsuki's eyes dilate and hips twitch each time his cock dips inside. His stomach is in the way to allow it any deeper though and Izuku swallows down a sob at the mounting frustration.
"Please, alpha." Izuku whimpers. "Need you, Kacchan. Please."
He doesn't even know what he's pleading for but his alpha wastes no time manhandling Izuku again, shucking off his wet sleep shirt and practically ripping apart his little panties. He moves Izuku so he's laying on his side, lifting his leg up and then, unceremoniously, he pushes into his waiting pussy. Izuku yelps at both the sudden feeling of fullness and the warm wet mouth that simultaneously attaches itself to his nipple.
Kacchan is–
"Oh my god! Oh–"
He's nursing from him. His alpha is drinking his breast milk. Lapping up the dripping liquid that's spreading from his bloated tits all across his chest, then fixing that sinful mouth on his puffy nipple again and sucking hard.
Izuku groans from some place deep in his lungs. Not breaking from the task at hand, Katsuki continues to suckle but brings a hand to palm and grope at his neglected breast, adjusting himself and driving his cock deeper into Izuku's cunt.
The relief is instantaneous.
Izuku purrs at the delicious fullness of his alpha's cock stretching him out, filling him so good he can feel it kiss the spongy doughnut of his cervix. His pussy spasms around Katsuki's dick but the alpha simply huffs out a little shiver and pays so mind, eyes closed, too busy milking him with his mouth. The heaviness alleviates with each deep, drawn out suckle and Izuku slowly relaxes into the bed.
"Just like that, alpha. You're doing so well." He purrs.
His eyes lid over and he tangles his fingers in Katsuki's hair, smoothing down the sweaty locks and pressing his alpha closer, urging him to drink more from him. To take all he needs because Izuku wants to give.
To give, to nurture, to care for.
It feels good– cockwarming his beloved Kacchan and nursing him with his own milk. Makes him feel useful in a primal way he's never felt before. A good omega.
Suddenly, Katsuki growls and Izuku groans when the alpha gets fussy, nipping at his sensitive nipple and roughly squeezing his other breast like it's a stress ball. It makes milk squirt from him in a small spray, wetting them both with the sweet liquid.
"Oh fuck– no wait! Ah, Kacchan don't do that." He gently admonishes. He eases the alpha off of him, noticing that the red of Katsuki's eyes have reduced to but a pinprick of colour, almost completely engulfed by a ring of black. His alpha looks dazed, expression so eager and open as he licks his lips and gazes up at him. He looks almost pouty and Izuku coos in adoration.
"More 'Zuku." Katsuki rumbles, but the words are partially slurred into a whine. "Taste so good, omega. Gonna breed you and keep you fat and pupped forever." He bucks his hips and wrenches another gasping moan from Izuku when he shuffles around again to lick against his sternum, jostling the thick cock nestled deep inside him.
"Ah– Y–You want more, Kacchan? Please– you're doing so good for me, alpha." Izuku breathes, eyes fluttering shut and giving in to the quick urge to grind down again. His bare pussy throbs. Kacchan's cock is so big and feels so good, he can't help it.
His alpha mouths at him again and Izuku quickly guides Katsuki by the back of his head to his other tit. The alpha, alert but surprisingly docile, goes willingly; automatically taking the ignored enlarged bud into his mouth without promoting and giving it the same treatment as the one before; sucking, enthusiastic and greedy, and swallowing down the sweet milk in large, frantic gulps.
Fucked and pupped, with a fat cock in his cunt and a warm, eager mouth at his tit, Izuku suddenly feels all the tension and earlier discomfort bleed away from him. Mind blissfully blank, he pets Katsuki's hair, hugging him close as he closes his eyes and let's his thoughts drift into that hazy, floaty space it sometimes ends up in.
It's silent then. Only the soft sounds of suckling and the periodic squelch of his pussy clamping down on Kacchan's cock breaks the quiet.
They drift off to sleep like that.
The joys of pregnancy means sometimes Izuku wakes up in the middle of the night, horny and leaking– from more places than one. Thankfully, his alpha is only too eager to take responsibility and help him out.