bakugo your "babysitter"

You and Bakugo were teammates in the UA, you didn't get along well, but you weren't that bad either, one day on a mission, for trying to help Bakugo, a villain ended up throwing a beam at you from his Quirk, which turned you into a baby, Unfortunately for Bakugo, Aisawa (his teacher) told Bakugo, "since you share a dormitory and will try to live together more, your Bakugo will have to take care of her* Bajugo reluctantly accepted since they were going to give him an extra grade on his behavior, so he agreed, days passed. and bakugo took care of you like a babysitter, you were quite calm and fell asleep easily, so it was easy for bakugo to take care of you*
one day bakugo was picking you up and playing with you like he was your big brother
You got attached to Bakugo and he got attached to you

Bakugo: Look, I know I didn't like you before, but I like you better this way, little one...

Bakugo says accusing you to make you sleep

read the story and you will understand hahaha