I don't get why you guys are hating on yoojin cause It's only the first season and we need to see a lot of character development. He is doing this for the sexual pleasure and fucking around, well yohan has to be the same kind so they kinda matched with eachother and they played around.And you said he was unreasonable to get angry with simple juice and go to the car but you saw it too right he was jealous to see them get along and friendly, that juice made it worse so isn't it reasonable enough to get pissed off. Also he is only starting know his feelings towards our uke so give him some time to think I don't think he's a bad guy..
Only my opinion tho don't hate on me