Aizawa had to work as a a pro hero, so they were babysitting you. You weren't impressed regarding the fact you were twelve and could literally live on your own in a forest with nothing.

Bakugo: "Fucking hell..."

Mina: "Bakugo! You can't swear around this kid."

Kirishima: "Mina, it's Aizawa's kid. It'll be fine."