The bf's are hajin and dokyung(the black haired and greenish blue haired) the white haired boy is baehyuk, hajin's ex who is obssessed with hajin, you shoul reread it or maybe this'll help.
Ok, I see a lot of confused people in the comments, first off, dohyun is the black/brown haired guy, who is in a relationship with hajin, taehyun is the blond guy who has a crush on dohyun and hajin is taehyun's uncle.
Before the flashback, hajin and taehyun had a fight, because hajin thinks that taehyun doesn't trust him enough to tell him about important things like his problems, then when things settle down with them, I think that's when dohyun wanted to know more about taehyun, baehyuk and hajin's relationship, that's when the flashback happens.
FLASHBACK:
Basically, taehyun became a kid again so he can take care of hajin while hajin's in the middle of becoming a vampire. Baehyuk, hajin's ex crush suddenly became possessive of hajin because of certain events that happened to hajin, Baehyuk bacame violent to anyone who was talking or even staring at hajin, and Baehyuk manipulated hajin into trusting only him.Taehyun saw how depressed hajin became cause of Baehyuk's violence towards his classmates, and how no one wanted to be friends with hajin anymore. Taehyun and hajin fought, cause taehyun was trying to convince hajin to break up with Baehyuk, but since he manipulated hajin, he got mad with taehyun and told him "you don't know anything" they didn't talk for 6 months. Taehyun really wanted to help hajin get away from Baehyuk, but he needed to have hajin's trust again, so he talked to hajin again and told him he was also a vampire, they made up, but hajin was still with baehyuk. but when dohyun met hajin, that was the time hajin was finally free, that's why taehyun was greatful to dohyun.
Then, this is after the flashback, which shows us a new unknown but hot character that is probably dohyun's big or little brother cause they look so much alike but who knows(〜￣△￣)〜
Sorry the name was dokyung not dohyun
OMG THX SO MUCH I THOUGHT THE NEW DUDE WAS DOKYUNG (づ￣ ³￣)づ
Awww welcomee
Who are they whose the bf and who isnt is white hair boy here i don’t understand