Can someone explain (spoilers) why yohan is so angry?

I assume he feels humiliated by Jun, I mean Jun knows the weakest side of Yohan and the reasons for that and generally all of his situation but still does what he does in that scene. Clearly Jun wants to help, yet Yohan might see it as an act against him (specially when we consider all the bad and hateful feelings he bears for his family). For me, that would be reasonable enough to become mad. But I haven't read the novel, so this is no valid thing just my opinion.

It's just an act haha