It was all Dongsookie at first, Until Donghyuck had to pretend he was his sister. And keep up the promise, "I wont fall in love with your boyfriend" starts getting harder. Mark was such a gentlemen. And Dongsookie was pregnant.
When Mark is attracted to Donghyuck sexually whilst Donghyuck is actually in love with Mark and only gives him because he loves him too much to say no,Will Mark realise that he is hurting his best friend and find out that he is actually in love with Donghyuck??
Read.More.To.Find.Out.