The nausea had been constant for a week. A low, rolling tide in Izuku’s gut that rose every morning and lingered through afternoon practice. His breasts ached, a deep, sensitive throb that made the brush of his sports bra feel like sandpaper. He’d caught his reflection in the locker room mirror, hands pressing against the soft curve of his lower belly, wondering when his cheer shorts had gotten so tight.

“You look green, Izuku,” Ochako said, tossing her gym bag over her shoulder. She grinned. “And not just your hair. You puking again?”

“Maybe.” Izuku leaned against the cool metal of the locker, swallowing against the sour taste in his mouth.

“Classic camp crud,” she said, then winked. “Or maybe you’re pregnant.”

She laughed, a bright, careless sound, and walked out. The words didn’t register as a joke. They landed like stones. One after another. Pregnant. Pregnant. Pregnant.

Izuku’s hands flew to his mouth. His mind replayed the cabin. The lake. The porch. Every desperate, reckless time he’d begged. *Come inside me, Daddy. I need it. Please.* The memory was a physical blow. He stumbled through the locker room to where is father's office was.

He found Katsuki in his office, reviewing film at his desk. Izuku didn’t knock. He just burst in, his face pale, eyes wild. “Daddy.”

Katsuki’s head snapped up, the scowl already forming. “What?”

“I think…” Izuku’s voice shattered. He wrapped his arms around his tender chest. “I think I’m pregnant.”

The room went utterly still. The only sound was the faint hum of the computer fan. Katsuki’s red eyes locked on him, wide, unblinking. His knuckles went white where they gripped the edge of the desk.

“Say that again.” The command was flat. Dead.

“I’m sick all the time. My… my chest hurts. I’m getting fat.” Tears spilled over, tracing paths through his freckles. “Ochako just said it as a joke, but it’s not a joke, is it? We… we didn’t stop. Not once.”

Katsuki stood. The movement was slow, deliberate, like a predator uncoiling. He came around the desk, his shadow swallowing Izuku in the dim office light. He didn’t touch him. Just looked. His gaze dropped to Izuku’s stomach, then back up to his terrified face.

“Fuck,” Katsuki breathed, the word a raw scrape of sound.

“What do we do?” Izuku whispered.

Katsuki’s jaw worked. He reached out, not to comfort, but to turn Izuku’s face toward the lamp light, studying him. His thumb brushed a tear away, the calloused pad rough against soft skin. “We find out.”

He turned, snatched his phone from the desk, and stabbed a number. His voice was all coach—clipped, authoritative, leaving no room for question. “Yeah. I need an appointment. Today. For my son.” A pause. “No. It’s private. Discretion is non-negotiable.” He listened, his eyes never leaving Izuku’s trembling form. “Two hours. Good.”

He ended the call. The silence that followed was heavier than before, thick with the unsaid. With possibility. With catastrophe.

“Get your things,” Katsuki said, his voice low. “We’re going to the doctor.”

Katsuki’s hand, still cradling Izuku’s tear-stained face, slid to the back of his neck. He pulled him in, not gently, and covered his mouth with his own.

The kiss wasn’t soft. It was a claim. A silent promise in the dark office. Katsuki’s tongue swept past his son’s lips, tasting salt and panic, and Izuku melted into him with a broken whimper.

When he pulled back, their breath mingled in the narrow space between them. “Listen to me,” Katsuki growled, his forehead pressed to Izuku’s. “No matter what that test says, it’s gonna be okay. You hear me? Daddy’s got you.”

“But—”

“No buts.” His thumb brushed Izuku’s swollen lower lip. “We handle it. We always handle it. Now get your bag. Car’s out back.”

The drive to the discreet, private clinic was a twenty-minute stretch of suffocating silence. Izuku stared out the passenger window, hands folded over his tender stomach. Katsuki’s knuckles were white on the steering wheel, his jaw a hard line in the dashboard glow.

He parked in a reserved spot behind a nondescript brick building. “This place is discreet. They ask no questions.” He looked over at Izuku, who hadn’t moved. “Come on, nerd. We’re going in.”

The exam room was cold. Stark white walls, a narrow table covered in crackling paper, the sharp scent of antiseptic undercut by leather from the doctor’s chair. A middle-aged woman in a lab coat entered, her expression professionally neutral.

“We’ll do a blood draw first for the most accurate result,” she said, her voice calm as she prepared a needle. Izuku flinched when the tourniquet tightened on his thin arm.

“Look at me,” Katsuki ordered from his chair against the wall. Izuku’s wide green eyes found his. Katsuki held his gaze, steady, unblinking, as the needle slid in. “Good. Just breathe.”

After the blood was taken, the doctor performed a transabdominal ultrasound, explaining it was standard for a comprehensive confirmation. She squeezed cold, clear gel onto Izuku’s lower belly. Izuku gasped at the touch, his fingers digging into the paper sheet.

The room filled with a staticky, rhythmic whoosh. The doctor moved the wand, her eyes on the monitor. She was quiet for a long moment, her face unreadable. Then she nodded, a single, definitive motion.

“The quantitative hCG levels from the blood are conclusive,” she said, turning to look at Katsuki, then at Izuku. “And the ultrasound visual confirms it. You are pregnant, Mr. Bakugou. Approximately eight weeks along.”

The whooshing sound—the heartbeat—continued to fill the room. Izuku’s breath hitched. He turned his head on the paper pillow, his freckled face pale, his eyes drowning as they locked onto his father’s.

Katsuki didn’t move. He didn’t blink. He just stared back at his son, the machine’s rhythmic proof of their sin echoing between them, and slowly, deliberately, gave a single, imperceptible nod.

Katsuki’s eyes never leave Izuku’s as he addresses the doctor, his voice a low rumble. “Give us a minute.”

The doctor nods, her professional mask firmly in place, and slips out, closing the door with a soft click. The sound of the lock engaging is louder.

The rhythmic whoosh of the fetal heartbeat still pumps from the ultrasound machine’s speakers.

For three full seconds, they just stare at each other across the cold, paper-covered room. Then the dam breaks.

Katsuki is on him in two strides, his hands cupping Izuku’s face, his mouth crashing down. It’s not a kiss. It’s a collision. Teeth clash. Izuku’s moan is swallowed whole as he arches up from the table, the paper tearing beneath him. He claws at his father’s polo, fumbling for the buckle of his belt.

“Daddy—" Izuku gasps when Katsuki rips his mouth away to bite at his throat.

“You hear that?” Katsuki growls against his skin, his own breathing ragged. The *whoosh-whoosh-whoosh* fills the room. “That’s my kid in your belly. Mine.”

“You did it,” Izuku sobs, his fingers finally yanking Katsuki’s belt open, button popping. “You really bred me. Just like you promised.”

Katsuki’s hands shove the short skirt of Izuku’s uniform up to his waist. He doesn’t bother with the panties. He hooks his fingers in the lace at the hips and pulls, hard. The fabric gives with a sharp rip, baring him. Katsuki’s palm slaps down on Izuku’s lower belly, a hot, possessive brand over the place where the proof is growing. “My seed took. Fuck. My little boy’s gonna have my baby.”

He fumbles his own jeans open, and his cock springs free, thick and already dripping, an angry red curve against the sterile white of the room. He spits into his hand, slicks himself roughly, and notches his head at Izuku’s entrance. It’s already slick, dripping for him.

“Look at me,” Katsuki commands, his voice shredded.

Izuku’s green eyes, wide and wet, lock onto his. Katsuki pushes forward.

The stretch is immediate, breathtaking. Izuku cries out, a sharp, broken sound that gets swallowed by the machine’s heartbeat. Katsuki sinks in to the hilt in one brutal, claiming thrust, his hips meeting the backs of Izuku’s thighs, pinning him to the table.

“Oh, god—Daddy—!”

“That’s it,” Katsuki grunts, already pulling back and slamming home again. The exam table rattles against the wall. “That’s my pregnant boy. Taking his Daddy’s dick just like he begged for. Every fucking time.”

Izuku’s legs wrap around his waist, heels digging into the small of Katsuki’s back. “Harder! Please, I need—I need to feel it—!”

Katsuki obeys. His thrusts are frantic, piston-hard, each one jolting Izuku up the table. The paper shreds beneath them. The cold gel from the ultrasound smears between their bodies. Katsuki’s focus is absolute, his red eyes burning into Izuku’s, watching every flinch, every tear, every slack-jawed gasp.

“You wanted my attention?” Katsuki pants, driving into him. “You got it, nerd. You got all of it. You got my kid in your guts. You’re mine now. You hear that? Mine.”

“Yours!” Izuku screams, his body bowing. “Always yours, Daddy! Breed me more! Fill me up again!”

The obscene, wet slap of skin on skin mixes with the relentless heartbeat from the speakers. It’s a frantic, desperate rhythm. Katsuki’s hand snakes between them, his thumb finding Izuku’s swollen clit.

Izuku comes instantly, his cunt clenching like a vise around Katsuki’s driving cock. He squirts, a hot rush that soaks the torn paper and drips onto the leather exam stool below. The sound he makes is pure animal relief.

It tips Katsuki over the edge. With a final, deep grind, he buries himself as far as he can go and empties himself inside his son. His roar is guttural, raw, drowning out the machine for a three-second eternity. He pulses, filling the womb he’s already claimed.

Katsuki stays buried inside him, pulsing, his forehead pressed to Izuku’s. The fetal heartbeat still fills the room. His whisper is a raw scrape against Izuku’s ear. “You’re gonna swell up. Get soft and round. Everyone’s gonna see what I did to you.”

Izuku’s legs tremble around his waist. “Daddy.”

“They’ll see my mark on you,” Katsuki continues, his voice low and relentless. “Your little tits’ll get heavy. Your nipples’ll get darker. Every time you puke in the morning, that’s me. Every ache in your back, that’s my kid making room.”

“I wanted it,” Izuku breathes, his cunt giving a weak, fluttering squeeze around Katsuki’s softening cock. “I wanted you to own me like this.”

Katsuki finally pulls out, a slow, wet slide. He looks down between Izuku’s spread thighs. His come is already leaking out, dripping onto the ruined paper, mixing with Izuku’s squirt. The sight makes his spent cock twitch. He spits on his fingers and pushes them back inside, messy, possessive.

“Gotta keep it in,” he grunts, working his fingers. “Let it take.”

Izuku whimpers, oversensitive. “It already took.”

“Might take again.” Katsuki withdraws his fingers, smearing the mess over Izuku’s lower belly, over the place the ultrasound wand had been. He finally looks at the monitor. The black-and-white image is still frozen there, a grainy, bean-shaped shadow. His throat tightens. “Fuck.”

“Is it…” Izuku starts, then stops, his voice small. “Is it really in there?”

“You heard the heartbeat, nerd. Saw the screen.” Katsuki’s hand settles over Izuku’s belly again, a heavy, warm weight. “It’s in there. Growing.”

Izuku covers Katsuki’s hand with his own. His fingers are ice cold. “What do we do?”

The question hangs in the antiseptic air. The machine’s rhythmic whoosh is the only answer for a long moment.

“We go home,” Katsuki says finally, his voice devoid of its earlier frenzy, flat and practical. “You’re gonna be sick. You’re gonna need things. We figure it out.”

“Figure it out,” Izuku echoes, not quite a question. He looks suddenly very young, pale and freckled on the stark white paper, his cheer skirt bunched at his waist, his top shoved up. “Mom.”

Katsuki’s jaw clenches. “Not now.” He moves away, pulling up his jeans and fastening his belt with sharp, efficient motions. He finds a box of tissues on the counter, pulls a wad, and comes back to the table. He doesn’t hand them to Izuku. He cleans him himself, wiping roughly between his thighs, over his belly, his movements oddly tender despite their force.

Izuku watches him, silent. When Katsuki is done, he sits up slowly, wincing. The torn, wet panties are a lost cause. He lets them fall to the floor.

“I’ve got you,” Katsuki says. It’s not gentle. It’s a fact.

Into that silence, Izuku whispers, “You’re really going to be a daddy.”

Katsuki looks at him. His red eyes are exhausted, dark, full of a terrifying wonder. “I already am.” He pulls Izuku closer. “Now I’m gonna be a grandfather, too. Come on. Time to go.”