MHA Age Regression Oneshots 💛

ShinSero

A/N: I hope you don't mind me interrupting the update list, I really wanted to write this. Enjoy!

UNEDITED

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Shinsou had been in America for a month and Sero was struggling a lot. He missed his caregiver more and more every day. He knew the internship was important to Shinsou but he didn't know how long he could take the distance anymore.

Sero had just gotten back from his last training session of the day and was desperate to call Shinsou. He knew it was pretty early but he couldn't take it anymore. He picked up his phone and clicked on the contact, praying he'd pick up.

It rang a couple of times before a groggy "Hello?" was heard from the other end. Sero was ecstatic. Hearing Shinou's voice instantly made him feel a little better. In fact, it made him regress. That wasn't his intention when he called but couldn't help it.

" Papa!" he said, excitedly. Of course, Shinsou knew that meant his boyfriend had regressed. Which he had no problem with but it was seven in the morning and he was exhausted. Would that stop him from spending time with his baby? No, absolutely not.

" Hi, baby boy, how're you doin?" he asked, sitting up in his bed. If he stayed laying down much longer he'd fall asleep on the call and if he did that, he'd feel awful. He knew Sero was struggling so he was doing his best to spend all the time he could with him.

Sero could hear the tiredness in Shinsou's voice and it made him feel really bad. Shinsou was working hard and he needed all the rest he could get. " 'm otay, jus misses you lots, Papa. I waked you ups?" he asked, worried.

" Yeah, but that's alright, bubs. My alarm was about to go off anyway. Papa misses you too, sweet boy. Have you been a good boy for your uncles and aunties?" Shinsou asked the class to help babysit Sero for him while he was gone. Of course, they were all happy to help. Especially, Kaminari and his caregiver, Bakugo. When Shinsou was home, they hung out all the time. Kaminari was Sero's best friend both when little and big so while the two littles played, the caregivers spoke and watched over them.

Shinsou had just spoken with Bakugo a few days before to ask how Sero was. He'd told him he was doing well just having a couple of fits here and there when he missed his Papa too much. Shinsou wasn't surprised by that, he expected it. It was a hard transition from seeing each other every single day to not being able to be together for three months.

" Mhm! I bein nice an shawin my toys wif Kami an eatin my veggies an not makin messes an evyfing!" he said. Little Sero was doing his best to behave, hoping maybe if he was good enough, Shinsou would come earlier. Shinsou knew this, he and Bakugo had spoken about it before. He was happy he was behaving but he felt so horrible about the reasoning.

" That's my good boy, I'm so proud of you, prince!" Shinsou said, knowing how much it helped Sero to be praised. Just then, there was a knock at Sero's door. He jumped from his bed, the phone still pressed to his ear, and opened the door to reveal Kaminari and Bakugo.

Kaminari was regressed as well, a stuffie in his hand and a paci in his mouth. " Roro! Miss you!" Kaminari said, throwing himself at Sero for a big hug. The two hugged while Bakugo walked into the room and set Kaminari's stuff down. " Miss you too, Kami! Oh, I talkin to Papa, see?" Sero shoved the phone in Kaminari's face, the blond saying an excited greeting.

" Hey, buddy, why don't you facetime your Papa on your laptop? That might be a little easier for everyone." Sero nodded his head in agreement and grabbed his laptop. Bakugo took the phone from Sero and explained to Shinsou that he was going to hang up but Sero would call him on his laptop in just a second. He hung up the phone and placed it on Sero's nightstand on the charger.

...

Shinsou and Sero had been on the phone for a couple of hours now, Bakugo and Kaminari chiming in every once in a while. But it was getting close to the time for Shinsou to leave for his agency and Sero needed to start winding down before bed. It wasn't quite late enough for him to go to bed but he wanted him to get ready early so Bakugo wouldn't be up too late fighting a sleepy Sero into the bath.

" Bubba, Papa has to go soon. Can you be a good boy for me and let Uncle Suki get you ready for bed?" Sero's smile dropped, he didn't want his Papa to go! Once Shinsou saw the look on his baby's face, he knew it was going to be a fight.

Sero pouted and crossed his arms over his chest in protest. " No, Papa! Don' wants you ta go! An not seepy, no seeps!" he fought. Bakugo left Kaminari to finish coloring his picture and went over to Sero to try and defuse the situation.

" Hey, baby, Papa really has to go. If you're good and let me get you ready for bed, I'll give you an extra treat after your bath!" Bakugo said. Shinsou was so grateful Bakugo was there with Sero because he knew he'd never be able to get off of the call if he wasn't.

Sero's shoulders relaxed and he uncrossed his arms, letting them fall to his sides. " But don' wanna say bye bye yets. Too sad, Suki," that broke both caregivers' hearts. It was sad to see Sero hurting so much but there was nothing either of them could do.

" I know, sweetheart. It is really sad to say bye bye but he's gotta go for now." Sero nodded his head, tears starting to form in his eyes. He looked back up at his screen towards Shinsou, he felt Bakugo rub his back gently.

" You weally gots ta go?" he asked, sadly. Shinsou nodded his head, a small frown on his face. He hated this part.

" Yeah, baby, I do. But I'll call you as soon as I get back, ok? I love you so so so much and I miss you lots and lots. Be good for me, bubba, text me before you go to bed." Sero nodded and said his goodbyes.

Bakugo hung up the phone and let Sero hug him for a bit. " It's ok, sugar, you'll see him soon. I pinky promise. Now let's get you and Kaminari ready for bed. You wanna have a sleepover?" Sero perked up at that a little. He loved having sleepovers with Kaminari and Bakugo!

The little nodded and began cleaning up his toys so he could get ready for bed. The three had a little routine while Shinsou was gone. Sero would come back to his dorm after classes and if he was regressed, he and Kaminari would go through their bedtime routine together, starting with cleaning up.

" Good job, bubs! Come on, Kami, time for a bath."

...

Sero did his best to behave despite how much he wanted to throw a fit about missing Shinsou. So, as promised, he got an extra treat after his bath. He got to pick any sweet that Sato had made during the week.

" Alright, little ones, time to brush your teeth and get you put to bed," Bakugo said, gently guiding them back up to Sero's room. Kaminari and Sero held hands as they walked to the restroom to brush their teeth. The two were truly inseparable.

...

Sero was settled into bed now, cuddled up with Kaminari while Bakugo went back to his dorm to finish up some homework. He grabbed his phone and texted Shinsou as he was told.

Nini papa I wove you!!!!!!!!

Shinsou didn't take long to respond, he was anticipating the text so he made sure he had his phone out around Sero's usual bedtime. He typed out his response and sent it, getting back to work shortly after.

Sero opened the text and smiled before placing his phone back down on his nightstand. He turned over and cuddled back up with Kaminari and fell peacefully to sleep. He was happy to have the company. He missed his caregiver so much but having such good friends really helped. 💛

A/N: Bro I had no idea how to end this, I swear I tried to make it cute. Ending one-shots is way more difficult than you'd think.