Cuz he felt immature for basically staking claim over junyoung. " I'm his long distant husband! " he prolly feels like someone his age shouldn't be getting jealous and acting out like that... Tho I thought it was super cute!!
Ah ok, thank you all for explaining ^^ . I was worried for a second, that he was hiding an illness or went mad or something. (I guess I read too many angsty stories recently XD)
Did he bang his head on purpose or went crazy for a second? And why?