How much have you read? I would guess you are at the beginning?
As for some of your questions here, the seme being a twin or not and the scene with the brown haired guy scene will be explained later in the chapters. Hajin and his former high school friend(Hangyum) did not date in the past.
If you have any more questions than what you posted here.
You can email me, and we can talk about this story! =^.^=
Little explanation here... spoiler if you haven’t read it.
They guy that he’s about to do the deed with (seme) is the same guy he went to high school with he also had a twin brother all along, he doesn’t want to tell the uke for some reason that hasn’t been explained yet but he’s pretending to be his twin brother so the uke won’t dislike the seme ( for unknown reason ) sorry if this made it even more confusing ( ̄∇ ̄")
i don't understand this!!!!!Is the seme an twin or really hajin's ex???And why are the're always weird "memories" or whatever in the middle of the story that don't make sense?(e.g. the sex scene with the brown haired guy)