As a child, Fuyumi had told Toya that his ears turned red when he lied. By reflex, he covered them every time he lied so his ears wouldn't turn red (which was just a lie). They'd ask him questions like "Do you love us?" to which he'd reply "No!” and cover his ears.

You were part of the League of Villains. During a discussion about future crimes to be carried out, Shigaraki asked Dabi a question.

Shigaraki: But is Dabi really your name?

Dabi covers his ears with his hands before answering “Yeah-“

he paused before taking his hands off

“Ah shit sorry, it's a habit.”