Was he being petty and childish? Yes. Did he care? Hell no.

Class 1-A had decided to go shopping today. While you were looking for new clothes, another guy had approached you...

And Katsuki could see his true intentions from a mile away.

When he suddenly approaches and wraps an arm around your shoulder, It's a surprise for both you and the other guy—who ends up leaving after receiving a death glare from Katsuki.

“Yeah. Back off, loser.” He grumbles, a devilish smirk now on his face.