Chapter Text
Natsuo sat a regressed, freshly bathed Shoto on his futon, then walked over to the closet to retrieve an oversized hoodie and a brand new package of diapers. He took a breath, preparing for a potential tantrum.
“Hey, squirt,” he said as he turned around, “How about we try wearing a diaper while you’re little?”
Shoto, who had been happily suckling his binky and running his hands over the fluffy towel he was wrapped in, looked up and frowned. “No,” he said around his pacifier. “No diapey.”
Natsuo sat down and toweled off his hair. This was expected; big Shoto hadn’t been very receptive to the idea either. “It’s up to you, bubs, but I think you would like it more than you’re expecting,” he said. “Wouldn’t it be nice to not worry about having an accident while you’re playing?”
Shoto wiggled around, trying to feel every soft fabric available as he thought about it. It was true, his bladder control went straight to hell when he regressed. So far, he’d had an accident in his pants while coloring, he’d wet the bed during a nap, and just a few minutes ago, he’d peed in the tub while Natsuo was bathing him. All on separate occasions, but still.
“Just humor Nat-nii for a little bit,” Natsuo suggested, wrangling baby Shoto into sitting up. He took his paci so that he could pull the hoodie over his head. “If you don’t like it, you don’t have to wear it.”
Shoto grunted as his head emerged, shaking his hair out of his eyes and making the hood slide off his head. He opened his mouth like a baby bird until Natsuo put the binky back in, then flapped his long sleeves and rotated the binky between his lips. “Otay.”
“Okay?” Natsuo said. Shoto bobbed his head, then rocked forward onto his hands and knees. He started crawling off the futon towards the simple wooden toy box sitting against the wall. He was on a mission. Natsuo chuckled and scooped him up, laying him on his back on the futon again. “Silly baby, we need to put the diaper on first. Or were you just gonna go half naked?”
Shoto didn’t really mind his relocation. He lifted his feet into the air and giggled as he tried to grab them. He caught the arches without a problem and rocked back and forth. Natsuo smiled at him, a not quite familiar but very soft warmth in his chest. (He never got to be a big brother, did he?) “Wow, good job! Look at how flexible you are! Such a strong little baby.” Shoto babbled back at him, a smile pure of tragedy beaming behind his pacifier.
Natsuo got up to grab the lotion and powder he’d stashed in Shoto’s designated “little” drawer. “You okay with me doing this, squirt?” he asked.
Shoto paused his rocking. What a silly question; of course he was okay with it. He trusted Nat-nii. Didn’t his big brother know that?
“Trus’ ‘ou,” Shoto mumbled. Words were hard right now, but Nat-nii was smart, so he would probably understand.
Natsuo blinked several times to will away the sudden sting in his eyes. He hadn’t expected such sudden and wholehearted trust. Natsuo had given his brother very little reason to trust him—they were perfect strangers until just a few months ago. Did Shoto give his trust to everyone that easily?
He must’ve been frozen for too long, because he was shocked out of his thoughts by Shoto’s pacifier bouncing off of his forehead. He gaped at Shoto for a moment, then laughed in disbelief. Shoto was pink-cheeked and giggly, proud that he was able to spit his binky that far and hit his target.
“You little booger,” Natsuo said, wiping his sleeve across his forehead to clear the traces of spit. “Okay. We need to lotion you first, like hell am I letting you get a diaper rash your first time wearing one.”
(Shoto drew in a tiny gasp and covered his mouth with his hands. Nat-nii said a bad word! What a scandalous caregiver he had!)
Natsuo tried to be efficient with the baby lotion; Shoto was getting squirmy, and Natsuo didn’t want to pause to wash off his paci or go grab one of his other comfort items. Still, he wanted to be thorough. Once every relevant patch of skin was properly moisturized, he ripped open the diaper package. Shoto’s face was cherry red as his eyes tracked the adult-sized diaper patterned with cute little polar bears, but he didn’t put up a fuss when Natsuo slid it under his naked bottom.
Natsuo finished with a dusting of powder, then taped the diaper closed. “Is that good, Sho?” he asked. Shoto wiggled on the bedding. It was a little awkward to have so much padding between his legs—he couldn’t even fully bring his thighs together. And it was odd to have a puffy cushion between his butt and the bedding. But… it wasn’t bad. It wasn’t bad at all. The diaper was soft inside and fit him comfortably; and above all, he was overwhelmed by the sense of security it offered him. Now he didn’t have to worry about having an accident, and that relief had him slipping even further, like his headspace had been begging him to. He felt fuzzy and warm and oh so safe with his big brother.
Shoto sat up and bounced a little, making his diaper crinkle. He giggled. Big Shoto may have been mortified, but baby Shoto was very much amused by his crinkly butt.
Natsuo chuckled again. “I’ll take that as a yes.”
Shoto beamed at him and bounced a couple more times, then made another break for his toy box. He still had a mission. “Wait, Sho! Don’t you want some jammie pants?”
Shoto paused again. Why would he need pants? He had all the coverage he needed. Nat-nii probably wasn’t being dumb on purpose, but that was now two silly questions he had asked. Maybe he wasn’t as smart as Shoto thought. That was okay; Shoto would still love his big brother even if he was a little dumb sometimes.
“No,” Shoto said, then went rummaging through his toy box. There wasn’t much in it, so it took only seconds for his little grabby hands to latch onto a ball of fluff. He smiled and pulled out a matcha-green bunny stuffie. It wore a tiny UA jacket that Momo had made for him after Shoto had told her that the bunny reminded him of one of his favorite heroes. Mission accomplished, he crawled back over to the futon and grabbed Noodle, his precious snow leopard stuffie. Noodle slept with Shoto even when he was big. Though, it was nice for Noodle to have a stuffie friend too. Maybe he could get a third friend for them soon.
The baby was happily babbling to his stuffies when Natsuo came over and ruffled his hair. “Hey, you haven’t had lunch yet. How about a bottle and some fruit?” he asked. Shoto’s eyes lit up, but then he looked down at his stuffies, conflicted. “They can come, too,” Natsuo added.
Oh. Well, conflict resolved.
After drinking a baby bottle of strawberry milk and being fed bite-sized pieces of yummy fruits, baby Shoto was dozing in his caregiver’s lap. They were sitting on the couch, a children’s nature documentary playing quietly in the background while Natsuo rocked them and read a book. Shoto gripped the front of Natsuo’s sweatshirt and snuggled further into the cradle of his arms. Natsuo had washed his pacifier in between lunch and cuddles, so now it was bobbing slowly in his mouth. He wasn’t sure how much time had passed since lunch, but he knew that he was sleepy and that his brother was holding him. He was so calm, so relaxed, and so very tiny.
Which is why he didn’t think much of it when his diaper grew warm. He shifted a little when dampness followed. Warm was fine, damp was not. He grunted and wiggled, drawing Natsuo’s attention. “What’s the matter, bubs?”
Shoto wasn’t even really sure himself, too deep in his babyspace. He whined and tugged at the front of his diaper. “Oohh, I see. Do you need a diaper change?” Natsuo asked. That’s when it clicked.
A memory from when five-year-old Shoto had an accident after his father wouldn’t allow him to use the bathroom during training surfaced like a mirror. How do you expect to control your quirk if you can’t control your body?
Shoto began to whimper and sniffle. No matter what Nat-nii said, only bad boys went potty in their pants; therefore, he was a bad boy. He was a bad, messy baby. The tears started rolling, and the loose fist that raised to scrub at his eyes did very little to stifle them. Crying was also bad; crying was another show of lost control.
Natsuo stood from the couch with Shoto in tow and carried him back to his bedroom before the tears could turn into a meltdown. “Shhh, it’s okay,” Natsuo murmured. He laid him down on the tatami floor, noting that they should order a changing mat if this was going to be a regular thing for Shoto’s littlespace. “You’re supposed to go potty in the diaper, that’s what it’s there for. You didn’t do anything wrong.” He grabbed the lotion and powder again, along with a fresh diaper and a pack of baby wipes.
Shoto sniffled as the wet diaper was untaped and his legs were pushed back. “M’bad,” he mumbled.
Natsuo froze. Did he hear that right? He must have, it didn’t sound like anything else. He shook his head and began wiping Shoto clean. “No, you’re good. You’re a good boy. You’re just a baby, babies can’t control when they go potty.”
Shoto hiccuped and coughed, on the cusp of arguing, but his tears were already beginning to wane. Maybe Nat-nii was right. And even if he wasn’t, Shoto realized that he was too tired to argue. He hadn’t actually had his nap yet, so he was already tired and a little cranky. But the icky feelings were fading with Natsuo’s gentle hands lotioning him, then sliding the fresh diaper under his bottom. He was powdered and taped, then Natsuo patted his tummy and said that he would be right back.
Shoto didn’t even have time to get fussy about being alone before Natsuo was back with freshly washed hands and the stuffies they’d left in the living room. He pulled Shoto into his lap right there on the floor, rocking him back and forth and combing his fingers through his hair. Shoto’s eyelids began to droop. He was fleetingly aware of Natsuo carrying him to his futon, tucking him in with his stuffies, and kissing his forehead before he sunk into a nap.
He got to be pampered and babied by his caregiver and didn’t have to worry about having an accident? Perhaps Nat-nii was right about the diapers after all.