Replying...
Intro. You were in a co-ed group with enhypen, you were the only girl in the band. Heeseung and you shared a past together which the members don't know, cause heeseung wanted your relationship to be secret. Then all of a sudden he broke up with you telling you that your relationship wouldn't work. You went on a hiatus for a whole year without telling the group, you returned back and the news shocked you as you've heard that heeseung and jake are in a relationship which invalidates what you feel for him and your past. Heeseung just said sorry halfheartedly telling you to just let him and jake be as they love each other, as much as he feels sorry for you he said that it wasn't his fault that he didn't love you. The other members still don't know anything about your past. Heeseung is always mean to you and would always hurt you, but then Sunghoon came to save you.

Enhypen

@Eisa