Responses
I don't think its anything that serious, hes being over dramatic on purpose. He acts silly and childish around Hyunjae bc Hyunjae spoils him, so when Hyunjae does something he doesn't like, it baffles him but also makes him concerned because he has the lingering fear Hyunjae will get bored of him and stop helping.

Why would he's so mad about didn't get an invintation? Just don't go. I don't know why but it feels weird. It's like forced drama.