The final bell rang. Katsuki Bakugo watched his students shuffle out, his gaze a predator’s stillness in the chaos. One pair of eyes didn’t look away. Green, wide, fixed on him from the third row. Izuku Midoriya. The boy jumped when their eyes met, scrambling to gather his books, a flush crawling up his neck.

“Midoriya.” Katsuki’s voice cut through the emptying room. “A word.”

The classroom emptied, leaving the late afternoon sun and the smell of chalk. Izuku stood by his desk, knuckles white on his backpack strap. “Y-yes, Mr. Bakugo?”

Katsuki leaned against his own desk, rolling his custom pen between his fingers. He let the silence stretch, watching the boy squirm. “You’ve been distracted. Staring. What’s on your mind?”

“Nothing! I’m sorry, I’ll pay better attention, I swear—”

“Not what I asked.” Katsuki’s tone was low, a teacher’s patience layered over something else. “Something’s bothering you. Tell me.”

Izuku’s mumble was almost inaudible. “It’s… it’s embarrassing.”

“I’m your teacher. It’s my job to help.” Katsuki took a slow step closer. The floorboard creaked. Izuku flinched. “Is it about your body?”

The boy’s head snapped up, eyes wide with panic. “How did you—?”

“A guess. You fidget. You blush. You avoid changing for gym.” Another step. The space between them was now just a few feet, charged and warm. “Talk to me, Izuku.”

The use of his first name did it. Izuku’s shoulders slumped, a confession deflating him. “My… my kitty,” he whispered, the childish word absurd and vulnerable in the quiet room. “It’s been… wet. All the time. Especially in class. I think something’s wrong with me. It’s never done that before.”

Katsuki’s blood went hot and still. He schooled his face into careful neutrality. “Wet how?”

“Like… sticky. Slick.” Izuku’s face was crimson. “It gets my underwear all… messy. And it happens when I look at…” He trailed off, his breath hitching.

“When you look at what?” Katsuki’s voice was a soft, dangerous pull.

Izuku’s green eyes, glistening with unshed tears of shame, lifted to meet his. “When I look at you, sir.”

Izuku’s eyes darted away, a full-body flinch. “N-no, I didn’t mean— I mean, it’s not like that, it’s just a weird feeling, I’m probably sick—”

“You’re not sick.” Katsuki’s voice was calm, a rock in the boy’s rushing panic. He took the final step, closing the distance. The late sun caught the dust motes swirling between them. “Look at me.”

Izuku’s breath hitched, but he obeyed, his green eyes swimming with confusion and shame.

“That wetness,” Katsuki said, his words deliberate, soft. “It’s called arousal. Your body is responding to something it wants. To someone it wants.” He let that hang, watching the boy’s lips part. “It’s not wrong. It’s natural.”

“But… but it’s you,” Izuku whispered, the confession tearing out of him. “You’re my teacher.”

“I am.” Katsuki didn’t move away. His scent—clean soap and something darker, sharper—filled the space. “Do you trust me, Izuku?”

The boy nodded, a quick, desperate jerk of his head. “Yes, Mr. Bakugo.”

“Then let me help you understand.” Katsuki’s hand came up, not to touch, but to gesture toward the empty desks. “Sit.”

Izuku moved like he was in a dream, lowering himself onto the hard wooden chair of his desk. Katsuki pulled the teacher’s chair from the front of the room, its legs scraping loudly. He placed it directly in front of Izuku, sitting so their knees almost touched. The intimacy of it was staggering.

“Your… kitty,” Katsuki said, the word clinical in his mouth. “It gets wet to prepare for sex. For a man’s cock to slide inside. The wetter you are, the better it feels.”

Izuku’s face was on fire. He stared at his own hands, clenched in his lap. “I don’t… I don’t have a cock.”

“You don’t need one.” Katsuki leaned forward, elbows on his knees. “You’re built to take one. To be filled. The wetness is your body begging for it.” He paused, letting the image settle. “Is it begging now, Izuku?”

A tiny, choked sound escaped the boy. He squeezed his thighs together, a telltale press. Katsuki’s crimson eyes tracked the movement, missing nothing.

“It’s okay,” Katsuki murmured, his voice a low thrum. “You can tell me. This is a lesson. Nothing leaves this room.”

Izuku’s nod was barely perceptible. “Y-yes,” he breathed. “It’s… it’s happening right now.”

“Good boy.” The praise was a physical thing, and Izuku shuddered. “That’s very good. Your body is honest. It knows what it needs.” Katsuki let his gaze drift down, over the boy’s uniform pants, the soft curve of his hips. “Do you want to feel better? To understand the feeling?”

Izuku’s eyes were huge, locked on his teacher’s. He was trembling. The trust was absolute, terrifying. “Please,” he whispered.

Katsuki smiled, a slow, private curl of his lips. “Then listen carefully. This is your first lesson. Touch it,” Katsuki said, his voice a low command that vibrated in the warm, still air. “Right now. Show me where it’s wet.”

Izuku’s breath stopped. His hands, still clenched in his lap, turned to stone. “I… I can’t.”

“You can. You will.” Katsuki didn’t move from his chair, his knees still brushing the boy’s. His crimson eyes were fixed, unblinking. “This is the lesson. You need to understand your own body before anyone else can. Put your hand on your kitty.”

A whimper escaped Izuku’s throat. He looked down at his uniform pants, the dark green fabric of the gakuran stretched over his thighs. His fingers twitched. Slowly, as if moving through deep water, his right hand uncurled. He lifted it, hovering over his lap, trembling violently.

“Through the fabric first,” Katsuki instructed, his tone clinical, patient. “Just feel the heat. Tell me what you feel.”

Izuku’s palm pressed down. A full-body shudder wracked him, and his eyes screwed shut. “It’s… hot.”

“Good. And?”

“I can feel… the wet. It’s… it’s there.” Izuku’s voice was a mortified whisper. “It’s soaking through.”

Katsuki’s own cock throbbed, heavy and insistent, against his zipper. He kept his breathing even. “Now unbutton your pants.”

“Mr. Bakugo—”

“Do you trust me?”

The question was a weapon. Izuku’s eyes flew open, green and desperate. He nodded, his fingers fumbling for the button of his trousers. The click of it releasing was obscenely loud. The zipper’s rasp was worse.

“Now your underwear. Pull them down just enough. Just so your hand can fit.”

Tears of shame tracked through the constellations of freckles on Izuku’s cheeks, but he obeyed, hooking his thumbs into the waistband of his panties and tugging them down a few inches. That surprisely bald mound was revealed, and the soft, vulnerable flesh beneath. He kept his gaze locked on the floorboards, his chest heaving.

“Touch yourself, Izuku. Use your fingers. Find the wetness.”

Izuku’s hand slipped under the fabric. His entire body jolted, a sharp gasp tearing from his lips. His head fell back against the chair, throat exposed.

“What does it feel like?” Katsuki’s voice was closer now. He’d leaned in, his scent enveloping the boy.

“S-slick,” Izuku choked out. “Really slick. And… and hot. My fingers… they’re sliding.”

“That’s your body’s proof. It’s ready.” Katsuki watched the boy’s hand move under the fabric, a subtle, frantic shifting. “Is your little clit hard? That nub at the top. Feel for it.”

Izuku’s brow furrowed in concentration, his muttering habit taking over even here. “I… I think so? It feels… bigger. Sensitive. Oh—” His hips gave a tiny, involuntary jerk.

“There it is,” Katsuki purred. “That’s a good sign. It means you’re enjoying this. Your body likes my lesson.” He let the silence fill with the soft, wet sounds of Izuku’s exploration. "Now take them off," Katsuki said, his voice leaving no room for air. "The panties. All the way. And spread your legs for me. Show me what's been making you so wet."

Izuku's breath hitched, a wet, ragged sound. His fingers, still slick from his own touch, fumbled at the waistband. He lifted his hips, a clumsy, shameful motion, and tugged the white cotton down his thighs, past his knees, letting them fall to the floor around his ankles. The classroom air felt shockingly cool on his exposed skin.

"Wider," Katsuki commanded, his gaze a physical weight. "Let me see."

Izuku obeyed, letting his knees fall apart, his feet still planted on the floor. He was completely open, the late sun from the blinds painting stripes across his inner thighs and the hair free cunny between them. His face was turned to the side, pressed against the cold wood of the chair back, tears still drying on his freckled cheeks.

"Look at me, Izuku." Katsuki waited until those wide, glistening green eyes met his. "Now use your fingers. Spread yourself open. Show me everything."

A sob caught in Izuku's throat, but his hands moved. One trembling hand went to the top of his slit, fingers pressing into the soft, swollen flesh. The other went lower, his touch feather-light. He pulled, revealing the glistening, pink interior, utterly vulnerable and dripping.

Katsuki's cock gave a vicious throb, straining against his slacks. He leaned forward, elbows on his knees, his eyes tracing every detail. "Good. That's very good. Now listen. This is your anatomy." His finger pointed, not touching, but close enough that Izuku could feel the heat. "The little nub you found, the sensitive one. That's your clit. It's the center of your pleasure. And these," he said, his voice a low, educational rumble as Izuku's fingers trembled, holding his lips apart, "are your labia. They protect the entrance. And this," his gaze dropped to the source of the slickness, the tight, fluttering hole, "is where you're meant to be filled. Where a cock would go. See how open you are? How wet? Your body is already learning. Now rub it," Katsuki said, his voice a low thrum in the quiet room. "Your clit. Use your fingers. Slow circles. Tell me what it does."

Izuku's breath shuddered out. His slick fingers found the swollen nub again. He pressed, a choked gasp escaping him. "It… it feels like a heartbeat. It's… really hard."

"Good. Keep going. Don't stop." Katsuki watched the boy's hand move, the frantic, unskilled circles. "Now slide a finger lower. Just one. Feel how wet you are. Feel the opening."

Izuku obeyed, his middle finger sliding down through the soaked folds. It caught at a tight, fluttering ring of muscle. He whined, high and desperate. "It's… there's a hole. It feels… it's squeezing my finger."

"That's your cunt, Izuku. It's hungry. Push against it. Just a little pressure."

Izuku pressed the pad of his finger against the tight entrance. His hips jerked off the chair, a silent plea. "It wants… I think it wants to open."

"It does," Katsuki breathed, his own hand gripping his thigh so hard his knuckles turned white. "It wants to be stretched. Filled. But not today. Today, you learn your own pleasure. Go back to your clit. Faster now."

The wet, rhythmic sounds filled the space between them. Izuku's muttering was a broken stream. "It's so hot, it's building, it feels like I need to pee, Kacchan, I'm scared—"

"You're not going to pee. That's your body getting ready. Let it happen. Don't fight it." Katsuki leaned closer, his scent of clean cotton and something darker wrapping around Izuku. "Look at me. Come for me. Show me what you are."

Izuku's eyes snapped open, glazed and drowning in green. His hand became a frantic blur between his legs, his back arching sharply off the chair. A broken cry tore from his throat—"Kacchan!"—and then it happened.

A gush of clear fluid shot from him, not a trickle but a sudden, surprising fountain, splashing over his trembling fingers and onto the worn classroom floorboards beneath his chair. He kept coming, wave after wave, his whole body seizing, a continuous, high-pitched whine pouring from his lips until he collapsed back, spent and shuddering.

The room was silent except for their ragged breathing. The smell of sex and salt hung thick in the chalk-dust air. Katsuki’s gaze was fixed on the puddle on the floor, then traveled up the boy’s glistening thighs to his utterly wrecked face. A slow, possessive smile spread across his features.

"Well," Katsuki said, his voice rough with a hunger he no longer bothered to hide. "That's a rare talent, Izuku. Your first lesson, and you’ve already shown me something extraordinary." He reached out, his thumb brushing a tear from the boy's cheek. "Clean yourself up. We're done for today."

Izuku stared, dazed, at the mess he’d made. His voice was a hollow whisper. "What… what was that?"

"That," Katsuki said, rising from his chair, his shadow engulfing the boy, "was your body accepting its purpose. Remember the feeling. I expect you to practice." He turned and walked to the window, looking out at the empty school grounds. "Get dressed. I'll see you tomorrow."