Izuku sighed as he walked down the hall towards his room.

"Such a dumb prank, seriously."

The boy was clad in only a towel as he half-ran back to his room. He'd been in the bathing room when someone had thought it would be funny to swipe his clothes. Now he was trying to hurry back with a towel secured around his waist hoping he wouldn't run into anyone. The idea of meeting Ochako like this made his face burn.

Thankfully he was almost there, he just had to go around the corner and-

"De-"

Someone small crashed into him as he went around, and while normally he would've stayed on his feet, it was surprising enough that he fell, the towel coming undone as he went down. He landed hard on his ass as he groaned, hearing a thump from in front of him too. He winced and looked up to see it had been Eri who'd run into him, and she sat up, rubbing her butt. She opened her eyes and mouth to speak but froze solid as she stared at him, her eyes going wide. Izuku was about to ask if something was wrong when he realized what she was staring at.

The towel was on the floor around him.

And she was looking between his legs.

"What's that?"

"AH! IT'S NOTHING! D-DON'T LOOK! FORGET YOU SAW IT!" he screeched, his face red as he grabbed the towel and got to his feet, his junk bouncing around as he wrapped the towel around himself. "A-Are you okay?"

"I wanna see it again. It looked weird," Eri replied as she stood as well.

"I-If you're okay, then excuse me!" he said as he rushed into his room. He was about to close the door when she slipped in just before it closed. Her eyes were locked onto his groin as she closed the door for them, and he stepped back towards his bed as she advanced.

"I wanna see it again. Please show me," she ordered surprisingly forcefully.

"I-I can't really show that to you, it wouldn't be appropriate, so please just-" He tried to protest but she ran forward, grabbed his towel and yanked it off before he could react, his nude body now on display to her. He fell back onto his bed as his hands shot between his legs. "E-ERI!"

"It looks different from mine," she said as she continued staring even as he remained concealed. "Why?"

"W-Well, men and women have different…p-parts…" His face felt more red than he could recall it ever being.

"Why won't you let me see it?" Eri asked.

"B-Because you're a kid, Eri! You're not supposed to see this kind of thing until you're older!!" Izuku cried.

"Why?"

"BECAUSE!"

"That's not a reason…" Eri replied as she came closer, to which Izuku felt himself scooting further back on the bed. Eri climbed onto the bed, driving him completely against the wall. In reality, Izuku knew he could easily overpower Eri and get her out of his room, but he was too stunned by her forcefulness to even consider it.

Eventually, she grabbed his hands and started trying to pull them away. At first, he fought back, which was easy to do, before he had a startling realization.

With a child like Eri, someone who hadn't seen much of the world at all, now presented with something she seemed annoyingly hyper-fixated on, it was likely if he didn't let her see it just a little bit, she'd keep asking about it. And if she did that in front of other people, that would only leave him open to questions he didn't want to answer. As horrible as it sounded, maybe showing her, just for a little bit, would be for the best.

"I-I'll show you…but you can't tell anyone else okay?"

"Why not?"

"Because…it just has to be a secret, okay?" Izuku asked. "Can you keep a secret?" Eri seemed to study him for a bit as she considered it, and then finally nodded.

"I will," she promised, and Izuku gulped. He knew this was a bad idea, a really really bad idea, but…it seemed better to satisfy her curiosity now so she wouldn't ask later.

He slowly removed his hands from his groin and presented his flaccid penis to the young girl, his face bright red. Her eyes widened as she gasped, leaning in for a better look, which only made him more embarrassed. "This is what a man's thing looks like?" she asked.

"Y-Yeah…"

"And you use it to pee?"

"Yep…"

"Why is it shaped like that?" Izuku felt himself choke. He couldn't tell her the actual reason, both because she was too young and because he doubted he'd be able to say it all without choking further.

"I-It's just-" he started, but thankfully he didn't have to finish, as she grabbed it before he could. "H-HEY-!" he then cried out, but a jolt ran through his body at her gentle fingers on his penis which made it twitch. Eri seemed to notice as she leaned in even closer, her face dangerously close. She moved it around to examine it from all angles, and although Izuku knew he should tell her to stop, to tell her that she'd seen enough, something was stopping him. The same thing that was making his dick begin to harden.

"It's getting harder," Eri said with confusion as the dick shifted and slowly started to straighten. "Is it supposed to do that?"

"I-It shouldn't be…" Izuku managed to get out, and within moments, it was at full mast in the girl's small hands.

"It's so much bigger now…" Eri said as she continued running her hands over it. It became harder to think as Izuku's moral compass was quickly falling out of alignment, his lower head taking over and forcing thoughts into his head he never would've had otherwise.

"E-Eri…" he struggled to speak, and she hummed as she looked up at him. He knew he shouldn't do this, shouldn't taint her like this, that this was wrong in every possible way, but he couldn't stop it. The words came out of his mouth. "Y-You should…lick it."

"Huh?" Eri asked as her nose crinkled. "Isn't that…gross?"

"No…it's something that adults do," Izuku went on even though part of his mind screamed for him to stop. "Just…try it."

"Okay," Eri said with a nod, all too trusting. She leaned in and stuck out her tongue, sliding it against his head. As soon as he felt the wet sensation touch his cock, he gasped, his entire body shuddering with delight. No wonder some people craved this kind of thing if it felt this good with just a single lick.

But of course, she didn't stop there. She licked at his head again, gently cupping his shaft as her wet tongue slid along his slit, then down to his shaft, every single touch sending fire through his body. His dick twitched as more and more of his rational thought eddied away. He wanted more.

"E-Eri…" he gasped, barely able to even speak. "U-Use…whole mouth…" Eri looked up at him, her tongue plastered against his cock, and that sight alone sent a hum through his bones. He prepared to try and explain himself more, but she seemed to understand as she pulled away just enough to open her mouth and place it entirely around the head of his cock.

Instantly, he felt like he'd died and gone to heaven. Nothing else in the world seemed to matter as her young mouth wrapped around his cock. And when she stuck her tongue out to press it against it, he felt a deep shudder through his entire being.

"M-More…" he begged, and she complied. She moved further down, though very slowly. It made sense, given that she didn't have a lot of space for his cock, which was considerable enough for her to have trouble with it.

But it wasn't enough. He wanted more, and his hands were already moving before he could stop them. They planted themselves in Eri's hair, and he slammed her down, his cock going down her throat. Her eyes went wide as she gagged, but he didn't care anymore. He wanted her, wanted her mouth, wanted it all inside her.

Using her hair to guide her, he started thrusting his hips at the same time he moved her head up and down, forcing his cock to go down her throat over and over. She gagged a few more times after that but seemed to get used to it surprisingly quickly. She gripped his waist tightly as she flicked her tongue out against his shaft, furthering his arousal. The pressure had already been building inside him for a while, and every second it became harder and harder to resist. He kept at it though, his head reeling back as grunts and groans escaped his lips with every passing second.

All it took was a few more seconds before he finally came. He slammed her head down as he erupted, hot sticky cum sliding down her throat at a feverish pace. Her eyes widened again as she gagged again at the bitter taste of it, but held firm as he released everything he had. Once he was done, he let go and she pulled away, retching and coughing. He laid against the wall, his dick softening as he let out a shaky breath. His clarity was returning, and the realization of what he'd just done struck him.

Yet when he looked down at Eri, ready to apologize, she was wiping her mouth but didn't look angry or upset at all.

"Did that feel good?" she asked. Izuku wanted to say no, to deny that it had been one of the best things he'd ever experienced, but-

"Yes," he replied honestly. "B-But remember, you can't tell anyone ever."

"I won't. But…" She fidgeted, "…are there other…adult things we can do that make you feel good."

Once again, Izuku was met with a decision, and some part of him lingering from before decided to answer instead of his rational side. "Yeah. There's actually some stuff we can do that makes us both feel good if you want."

"There is?" she asked so earnestly that he sighed, placing his hand on his face.

"Y-Yeah…" he replied. A moment later, he felt a shift, then something warm against his chest. He opened his eyes to find Eri snuggling against him.

"I wanna do it all with you," she replied, and while he opened his mouth to protest, the smile on her face was so genuine that instead, he closed it, laid a hand on her head, and began to pet her.

"Okay," he replied. "How about tomorrow?" Eri nodded, and that was that. Izuku laid his head on top of hers as he sighed once more.

What had he just gotten himself into?