Responses
Well, it's either a twin or he has a split personality. And Danwoo has sex with the "other" half not realizing this (only at the end of the act). I loved this webtoon so far (before the twin-sex scene), but this seriously creeps me out, I would rather him have a split personality than Danwoo accidentally sleeping with his twin

Honestly if there is a twin, I dont think he's fucking the bottom. When they were at dinner, he was so stiff with him... He might be sleeping with one but has the other brother monitoring their relationship for whatever reason. ┑( ̄Д  ̄)┍