The concrete steps of UA still hold the day's trapped heat, a low simmer against the soles of Izuku’s shoes. The air tastes like exhaust and fading sunlight. He’s halfway down, backpack slung over one shoulder, when he sees her.

Inko stands at the bottom, her hands clasped tight in front of her. Her floral perfume cuts through the urban smell a second before she looks up. Her eyes lock onto him. “Izuku.”

He freezes. The agreement was Katsuki wouldn’t pick him up today, a test of independence. This wasn’t the test. “Mom.”

“We need to talk, sweetheart. Please.” She takes a step up, her voice pitching into that familiar, pleading register. “Just come with me. We can go for coffee. I just want to talk to my daughter.”

The word lands like a slap. Izuku feels his stomach twist, a sick echo of the morning’s nausea. “Don’t.”

“Don’t what? I’m your mother. I’m worried about you.” She climbs another step, closer now. The campus behind him is quiet, the last stragglers already gone. “Living with him… it’s not healthy, Izuku. This rebellion. This phase.”

“It’s not a phase.” His own voice sounds flat, distant. “And it’s not a rebellion. It’s me.”

Inko’s face tightens. The kindness in her eyes has been replaced by a polished, clinical determination. “You’re confused. The stress of everything… it’s making you make choices you don’t understand. I found a doctor. A very good one. He specializes in helping girls work through these… identity crises.”

“I’m not a girl.” The words are ground out. He takes a step back, up the stairs. “I’m your son. And if you can’t see that, then you don’t get to talk to me at all.”

“He’s filling your head with lies!” The plea sharpens into a cry. She follows him, closing the distance. Her hand darts out, fingers brushing his wrist. “Can’t you see? He’s isolating you. Controlling you. What has he done to you?”

Izuku yanks his arm back. The touch burns. “He saved me.”

“From what? From me?” Inko’s laugh is a broken thing. “I love you. I want to fix this. He… he just wants to keep you. It’s sick. Can’t you feel how sick it is?”

Her words hang in the thick air. Izuku’s heart hammers against his ribs. He thinks of the cabin. Of the weight of Katsuki over him, inside him. The promise in the dark. *Our family.* It doesn’t feel sick. It feels like the only real thing he’s ever known.

“You don’t know anything,” Izuku whispers. He turns, heading back up toward the school doors, toward the lights, away from her.

“Izuku, wait!” Her footsteps are quick behind him. Desperate. “Please! Just listen! Your father… he’s not the man you think he is. He has feelings for you that aren’t right. A mother can see these things!”

He stops. The world narrows to the pulse in his throat. Slowly, he turns to face her. The setting sun glints off the windows behind her, framing her in fire. “What did you say?”

Inko’s mouth works. She sees she has his attention, and the clinical calm slides back over her panic. “I’ve seen the way he looks at you. It’s not… paternal. It’s possessive. Obsessive. He took you away from me because he wants you for himself. Don’t you see? He’s not protecting you. He’s claiming you.”

Izuku stares at her. The truth of it doesn’t land as a shock. It lands as a key, sliding into a lock he’s been trying to pick for months. It fits. It turns. A strange, cold calm settles over him. He takes a step down toward her, closing the gap until he can see the fine lines of fear around her eyes.

“You’re right,” Izuku says, his voice low and clear. “He did claim me.”

Inko blinks. “What?”

“I belong to him.” Izuku holds her gaze, green eyes steady. “And I want to.”

Inko’s face goes blank. The clinical calm shatters into pure, uncomprehending horror. “You… you what?”

“I’m pregnant,” Izuku repeats, the words solid as stone. “With his child. Our child.”

For a second, there’s only the distant traffic and the ragged sound of her breathing. Then her expression twists. The horror curdles into something hotter, uglier. Her hand flies out, a flash of motion in the dying light.

The slap cracks across his cheek, snapping his head to the side. The force sends him stumbling back, his shoe catching on the concrete step. He goes down hard, his backpack skidding away, his palms scraping rough against the ground.

“You slut,” Inko hisses, the word dripping with venom. She looms over him, her floral perfume now suffocating. “You filthy little harlot. You seduced your own father!”

Izuku tastes blood in his mouth. He pushes himself up on his elbows, staring up at her. The world tilts.

“This is your fault!” she screams, her voice shredding. “All of it! You poisoned him! You twisted him with your… your sickness! You’re a whore. A disgusting, sinful whore!”

Her hand draws back again, fingers curled into a claw, aimed for his face. Izuku flinches, braces for the impact.

It never comes.

A larger hand closes around Inko’s wrist, stopping it mid-air. The grip is absolute. Katsuki stands beside her, his expression a frozen storm. He must have used his quirk to get here. There’s no car, no sound of an approach. He’s just there. “Touch him again,” Katsuki says, his voice low and deadly calm. “And I break your arm.”

Inko gasps, trying to wrench free. His grip doesn’t budge. She turns wild eyes on him. “Katsuki! She’s lying! She’s saying these vile things to—”

“He,” Katsuki corrects, the single syllable a blade. “And he’s not lying.” He shoves her wrist away, sending her stumbling back a step. He doesn’t look at her again. His eyes are on Izuku, on the red mark blooming across his cheek, the blood at the corner of his mouth. Something dark and violent flickers in his crimson gaze.

Katsuki crouches down. His thumb brushes the blood from Izuku’s lip, the touch jarringly gentle. “You okay?”

Izuku nods, his breath hitching. The cold clarity is gone, replaced by a shaky, raw relief. “Daddy.”

“Yeah. I’m here.” Katsuki’s hand slides to the back of Izuku’s neck, a solid, grounding pressure. He helps him stand, keeping himself between Izuku and Inko. “Aizawa called. Said you might need a pickup.”

Inko stares, her chest heaving. The pieces are slotting together in her mind, and the picture is destroying her. “You… you knew? You know what she’s claiming?”

Katsuki’s arm slides around Izuku’s shoulders, pulling him close, his body a solid wall between his son and his ex wife. He doesn’t look away from Inko. “Say ‘she’ or ‘her’ again,” he says, his voice a low, controlled burn. “And I’ll make sure you regret it.”

Inko’s mouth opens, then closes. The fury in her eyes wars with a dawning, practical fear.

“You just assaulted my son,” Katsuki continues, the words clinical. “In front of a UA security camera. I’m sure it caught the whole thing. The slap. The fall. The names you called him.” He tilts his head slightly. “Leave. Now. Never contact us again. Do that, and I don’t call the police. You’re also breaking a protection order. You have no contact with *my* son. Not yours. Mine.”

“She is my child!” Inko chokes out, her hands clenched at her sides.

“You lost the right to call him that when you tried to ‘fix’ him.” Katsuki’s arm tightens around Izuku. “Walk away, Inko. This is your only warning.”

She stares at them, at the way Izuku leans into his father’s side, his face already bruising. Her expression cycles through rage, grief, and finally, a hollow defeat. She takes a stumbling step back, then another. Without another word, she turns and hurries down the steps, her figure swallowed by the evening shadows.

Katsuki watches until she’s gone. Only then does the rigid line of his shoulders loosen a fraction. He turns, both hands coming up to frame Izuku’s face, his thumbs gentle on the heated skin of his cheek. “Let me see.”

“I’m okay,” Izuku whispers, but his eyes are wide, wet.

“You’re not.” Katsuki’s thumb brushes the corner of his mouth again, wiping away a fresh bead of blood. “She hit you. Called you those things.” The dark flicker is back in his gaze, a promise of violence held on a very short leash. “I should have been here sooner.”

“You came.” Izuku leans into the touch, his own hand coming up to cover Katsuki’s. “You always come.”

Katsuki leans in, pressing his forehead against Izuku’s. Their breath mingles. “Always.”

Izuku lets out a wet, shaky laugh against his father’s forehead. “We need to go buy a pregnancy test.”

Katsuki goes still. He pulls back just enough to see Izuku’s face. “What?”

“Aizawa,” Izuku says, the name a key turning in a lock. “He figured it out. He’s pretty sure.” He watches the understanding dawn in Katsuki’s eyes, slow and then all at once. “I threw up in his class. He knew.”

Katsuki’s breath leaves him in a sharp, silent rush. His hands, still framing Izuku’s face, begin to tremble. It’s a minute vibration, but Izuku feels it against his bruised skin. The fierce crimson eyes glaze over, swimming with a shock so profound it strips every defense away.

“A test,” Katsuki echoes, his voice rough. “You need a test.”

“We need a test,” Izuku corrects softly.

A single tear tracks through the fine dusting of ash on Katsuki’s cheek, cutting a clean line. Then another. He doesn’t sob. He just stares at his son, his boy, as if seeing him for the first time all over again. His thumbs stroke Izuku’s cheekbones, reverent. “Our miracle,” he whispers.

He pulls Izuku into him then, arms banding around his shoulders, one hand cradling the back of his head. He holds him so tightly Izuku can feel the frantic hammer of his heart against his own chest. Katsuki’s face presses into the crook of Izuku’s neck, his breath hot and uneven.

“Daddy,” Izuku murmurs, his own tears soaking into Katsuki’s leather jacket.

Katsuki just holds him tighter. His shoulders shake once, a silent tremor of awe. When he finally speaks, his voice is muffled against Izuku’s skin. “You’re sure? He was sure?”

“He gave me a clinic referral. For confirmation.” Izuku tangles his fingers in the back of Katsuki’s shirt. “But yeah. He was sure.”

Katsuki pulls back again, his eyes red-rimmed but blazing. He looks from Izuku’s eyes to his mouth, to the faint, growing curve of his stomach beneath his school shirt. His hand slides down, palm flattening possessively over Izuku’s lower belly. “In here,” he says, wonder melting into a dark, fierce pride. “My kid. In my kid.”

Izuku covers Katsuki’s hand with his own. “Yeah, Daddy. Our kid.” Leans up and kisses his father, not caring if anyone sees.

Katsuki kisses him back, hard, right there on the UA steps. His mouth tastes like salt and smoke and a wild, desperate joy. He doesn’t care who sees. His hand stays pressed flat over Izuku’s stomach, a brand of ownership and awe.

“Our kid,” Katsuki breathes against his lips, the words a vow. He pulls back just enough to look at him, his eyes still wet. “Let’s go home.”

Three days later, they’re sitting in a sterile, beige examination room at the discreet clinic Aizawa had scribbled on a piece of paper. The air smells like antiseptic and lemon cleaner. Izuku’s hands are cold. He’s wearing a paper gown, the crinkly sound loud in the quiet.

Katsuki stands beside the exam table, a solid, immovable presence in black jeans and a tight grey t-shirt. He hasn’t sat down once. His arms are crossed, his gaze fixed on the door.

The door opens. A nurse in lavender scrubs comes in, her expression professionally neutral. She holds a tablet. “Izuku Bakugou?”

“Yeah.”

“And you are?” she asks, glancing at Katsuki.

“His father,” Katsuki says, the word dropping like a stone. “I’m staying.”

The nurse nods, unfazed. She looks at her tablet. “The blood test confirms it. You are pregnant. Based on your last reported cycle, we’re estimating you’re about six weeks along.”

The world narrows to the hum of the fluorescent lights. Izuku’s breath catches. He looks up at Katsuki.

Katsuki’s crossed arms have dropped to his sides. His hands are clenched into white-knuckled fists. He’s staring at the nurse, but he’s not seeing her. The rigid control he’s held since the school steps fractures, just for a second. A muscle in his jaw jumps. “Six weeks,” he echoes, his voice rough.

“That’s… that’s the cabin,” Izuku says softly, the math clicking. “The first time.”

Katsuki’s eyes snap to his. The heat in them is instantaneous, a physical wave. “Yeah.” He reaches out, his hand finding Izuku’s. His grip is almost painfully tight. “Our first time.”

The nurse continues, her tone gentle but detached. “We’ll need to schedule a follow-up for an ultrasound in a couple of weeks to get a more accurate date and check viability. I have some informational packets here about prenatal care, nutrition, what to expect.” She sets a small stack of brochures on the counter. “Do you have any questions for me right now?”

Izuku shakes his head, mute. He’s pregnant. It’s real. It’s in his blood, confirmed by science. A life started in a mountain cabin, in his father’s arms.

Katsuki’s thumb strokes over his knuckles. “We’re good,” he tells the nurse, his voice regaining its usual command. “Schedule the next appointment. We’ll take the earliest you have.”

Once they’re alone in the room again, the door shut, Katsuki turns. He doesn’t say a word. He just leans down, pressing his forehead to Izuku’s, his eyes closed. His breath shudders out. “Mine,” he whispers, a raw, broken sound. “You’re really carrying my kid.”

Izuku brings his hands up, framing Katsuki’s face. He feels the dampness on his father’s lashes. “Ours,” he corrects, his own voice thick. “Daddy… we’re really starting our family.”

Katsuki kisses him then, deep and slow and claiming, right there in the paper-gown sterility of the clinic. When he pulls back, his crimson eyes are blazing with a dark, triumphant fire. “Let’s go home,” he says again, but this time it sounds like a promise. “I need to fuck you until we can’t move to celebrate.”

Katsuki’s mouth is hot and demanding, his tongue sweeping past Izuku’s lips as his hands slide from his son’s face down to his hips, gripping the paper gown and bunching it up. The crinkling sound is obscenely loud in the sterile room. Izuku moans into the kiss, his own hands fisting in Katsuki’s grey t-shirt, pulling him closer until the hard edge of the exam table digs into his back.

“Daddy,” Izuku gasps, breaking the kiss only to dive back in, his teeth scraping Katsuki’s lower lip. “Right here. I need you right now.”

“Fuck, yes,” Katsuki growls, his voice ragged with awe and lust. He pushes the gown higher, his rough palms skating up the soft skin of Izuku’s thighs. “Gonna feel you. Gonna feel my kid inside you while I’m inside you.”

The door clicks open.

The same nurse in lavender scrubs stands frozen in the doorway, her professional neutrality shattered into wide-eyed shock. She clears her throat, the sound like a gunshot.

Katsuki jerks back, his body instinctively shifting to block Izuku from view. Izuku yanks the paper gown down, his face flaming. The air, charged with heat a second ago, turns brittle and cold.

“This is a medical facility,” the nurse says, her tone carefully flat, but her cheeks are pink. “We’ll need you to… save the celebration for home.”

“Right,” Katsuki barks, not looking at her. He’s already grabbing Izuku’s discarded clothes from the chair, his movements sharp with embarrassment and thwarted need. “We’re leaving.”

“Sorry,” Izuku mumbles, unable to meet the nurse’s eyes. He scrambles off the table, his legs shaky.

Izuku dress in a frantic, silent hurry, the nurse politely turning her back but not leaving. The drive home is a blur of tense silence and stolen, heated glances. Katsuki’s knuckles are white on the steering wheel. Izuku’s hand rests on his own stomach, his mind screaming one word on a loop: pregnant.

The moment their in their penthouse, Katsuki pins him against a wall. His body is a line of hard heat. “Six weeks,” he breathes against Izuku’s mouth, his hands already under his shirt. “My seed took in you the first time I ever had you. You understand what that means?”

“It means I’m yours,” Izuku whispers, arching into the touch. “Completely.”

“Damn right.” Katsuki kisses him, a deep, consuming possession. He walks him backward, never breaking contact, through the living room and into the bedroom. He doesn’t turn on the light. The late afternoon sun slants through the blinds, painting stripes across the rumpled sheets.

Katsuki lays him down like something precious, then strips his own clothes off with a brutal efficiency. He stands over him, naked and fully erect, his cock thick and heavy against his stomach. His eyes drink in Izuku, still half-dressed on the bed. “Show me,” he commands, his voice low. “Show me where my baby is.”

Izuku’s fingers tremble as he pushes his shirt up, baring his smooth stomach. The curve is subtle, just a soft rounding beneath his navel. Katsuki’s gaze locks onto it. He kneels on the bed, his hands following his eyes, palms spreading over Izuku’s belly as he leans down to kiss it, once, twice, his lips reverent.

Then his mouth moves lower, nuzzling through the fabric of Izuku’s pants, inhaling deeply. “You’re wet already,” he murmurs, the words vibrating against him. “For me. For this.”

“Always for you, Daddy,” Izuku gasps, his hips lifting off the bed.

Katsuki makes a raw, hungry sound and yanks his pants and underwear down in one rough pull. The cool air hits Izuku’s soaked skin for a second before Katsuki’s mouth is on him, his tongue laving a broad, wet stripe through his folds. Izuku cries out, his back bowing. Katsuki eats him like a man starved, his tongue circling his clit before plunging deep, tasting him, claiming the proof of his arousal and the new life growing within him in the same desperate act.

“Taste yourself,” Katsuki rasps, pulling back only to surge up and crush their mouths together, letting Izuku taste his own slick on his father’s tongue. “Taste how much you want this. How much your body wants my kid in it.”

Izuku claws at his back, sobbing with need. “Please. I need you inside. I need to feel you.”

Katsuki lines himself up, the broad, leaking head of his cock pressing against Izuku’s entrance. He pauses, his crimson eyes burning down into Izuku’s. “This is it,” he says, his voice trembling with a ferocious emotion. “This is where our family starts.”

He pushes in.

He pushes in, a slow, inexorable stretch that makes Izuku gasp, his body opening, accepting, his cunt clenching wet and hot around the invading thickness. Katsuki’s breath hitches, a ragged sound of awe, as he seats himself fully, his hips flush against Izuku’s ass, his heavy balls pressed tight. “Fuck,” he grunts, his forehead dropping to Izuku’s shoulder. “You feel that? You feel how deep I am?”

“Yes,” Izuku sobs, his legs wrapping around Katsuki’s waist, locking him in. “Daddy, you’re so deep.”

“Gonna stay right here for a minute,” Katsuki murmurs, his lips moving against Izuku’s throat. “Gonna let you feel every inch of me. Let my kid feel me.” He doesn’t move, just pulses inside him, a subtle, possessive rhythm. Izuku can feel the thick vein on the underside of his father’s cock throbbing against his inner walls.

“Talk to me,” Izuku whispers, his hands sliding up the corded muscles of Katsuki’s back. “Please.”

Katsuki lifts his head, his crimson eyes dark with a ferocious tenderness. “You’re so tight around me. So fucking perfect. My perfect boy, taking his father’s cock so good, making a baby with it.” He shifts, just a fraction, and Izuku cries out, the new angle brushing a spot that makes his vision blur. “That’s it. That’s where our baby is. Right there, where I can feel you.”

He begins to move then, a slow, rolling thrust that’s less about pace and more about depth, each withdrawal a teasing threat, each return a claiming. The wet, slick sound of their joining fills the dim room. Izuku claws at the sheets, then at Katsuki’s shoulders, his moans pitching higher with every drive.

“Look at me,” Katsuki commands, his voice gravel. Izuku’s green eyes, hazy with pleasure, snap to his. “You see who’s fucking you? You see who put this life in you?”

“You,” Izuku gasps, his back arching. “My Daddy. Only you.”

“Damn right.” Katsuki’s pace quickens, the slow rolls turning into harder, purposeful drives. The bedframe knocks softly against the wall with each thrust. He leans down, capturing Izuku’s mouth in a messy, biting kiss, swallowing his son’s whimpers. “Gonna fill you up again,” he rasps against his lips. “Gonna make sure it takes. Make sure you’re dripping with me for days.”

Izuku’s climax builds like a storm, tightening his belly, coiling at the base of his spine. “I’m close, I’m so close,” he chants, his heels digging into the small of Katsuki’s back.

“Cum for me,” Katsuki growls, his own control fraying, his thrusts becoming erratic, brutal. “Squirt on my cock, Izuku. Show me.”

The command shatters him. Izuku screams, his body seizing, his cunt clamping down in a brutal, milking rhythm around Katsuki’s length. A hot gush of liquid soaks them both as he squirts, the force of it pulsing around Katsuki’s cock.

The sensation tips Katsuki over the edge. With a raw, guttural shout, he buries himself to the hilt and spills, his release hot and endless inside the very place their child is growing. He collapses atop him, his full weight a grounding pressure, his face buried in Izuku’s neck as they both shudder through the aftershocks.

For a long time, the only sounds are their ragged breaths and the distant hum of the city below. Katsuki finally shifts, sliding out slowly, a thick trickle of his cum following. He doesn’t pull away. He settles on his side, one big hand splayed possessively over Izuku’s damp stomach again. “Six weeks,” he says quietly, his thumb stroking the soft skin.

Izuku turns his head on the pillow. The stripes of sunset light cut across his father’s face. “I love you so much, Daddy.”

Katsuki’s eyes meet his, the triumph still there. “I love you too, my baby boy.”