Responses
Sangwoo is too inmature and Jaeyoung is suffering because of that. You need to read again.
I feel they are both immature, this has been true for both throughout the whole series (literally from chapter 1). But something about this is different to me, they are both inexperienced in love and are obviously bound to make mistakes. Jaeyoung hasn't shown much interest in truly communicating what he feels without something angering him and that's causing both of them to suffer. Without honest, clear communication there is no way a relationship can survive.
i can't help but feel bad for sangwoo, he's obviously in pain over having to let jaeyoung go but there's something holding him back from being honest. in my opinion, jaeyoung has been acting real shitty with the whole US thing and i have a feeling it's gonna blow up in his face. i just hope they can get through it together (or else i might just stop believing in love )