i believe ppl are talking about the flashbacks:
in chapter 3, MC had a flashback of ML and same mole #2 being all lovely dovely, and said the reason why ML must like the hae-yool is bc he resemble same mole #2.
MC also caught ML and same mole #2 kissing in chapter 1 & 2! and same mole #2 said it was all MC's fault while he was getting neat up in chapter 2.
in chapter 11, MC thought of the family portrait of the ML's and the same mole #2 was in the picture, too.
so there are two characters with moles on their faces from MC's past.... although idk if the same mole #2 >@ ML's brother, or just MC and ML friend from the past (bc the female doc said them 3 were always hanging out together!) also, ML's brother died, too but we dont know how he looks like, yet.
if ppl are askin abt the other guy with same moles, guys its the same person as the blonde guy, but in the past, the mc and ml were like best friends back then or something, then sumt happened between them and they arent friends no more, the blonde guy js dyed his hair, but his original hair is black i guess, its the same person lmaoooo not a twin!!!