Jae is so bad at reading other people's emotions it's frankly embarrassing to be associated with it. Could not for the life of him figure out the problem, could not tell Curtain liked him, could not tell Curtain wanted to be friends, Curtain is so bad at just admitting to his emotions he would literally rather jump out a window than just say "Sorry I killed you, I feel bad about it".

Jae used one of Curtain's abilities to possess his body against his will and force him to have a conversation.