Wouldn't that be a rather predictable and not very realistic plot though. Jiwon has already shown to be extremely guarded and has traumatic flashbacks whenever any minor detail reminds him of his ex. For him to be able to completely recover or manage this, just by DG saying "I love you" would be a bit farfetched. In life such events rarely get closure, but instead the severity to how they effect a person can wax and wane. We don't even know the exact details of what happened with his ex, but Jiwon's reaction to his past is telling, it also shouldn't be that surprising that he still keeps a photo of his ex despite him causing him such grief, as it appears he played a major role in Jiwon's teenage and early adult years.
LOL. I normally love all of your postings, but this one made me laugh. I'm not as entertained by logic/normal/real life. I love thinking outside the box, and seeing others who have bent the box into another dimension.
Someone could tell me Alex's mask is the real face, and the other one is the fake, and I'd believe it.
Jiwon wears a mask in his real life too, he spoke previously about creating a "perfect image" of himself whilst at university. This is why the contrast to the image DG thinks of student council leader Jiwon/DG Alex and the actual Ahn Jiwon who has plenty of insecurities of his own, and only lets his guard down, it seems when drunk is gradually being shown. The problem is maybe that DG keeps idolising his favourite sunbae rather than be more aware to the reality of him.

Past is past Alex. Go and love donghyun.