Tbh they (Jeonghan & Kangwoo) relationship can't be saved, both of them wrong. Kangwoo, he too caution about he surrounding and how society look at they relationship, that make he can't see what his partner feel and what make is more worst is Jeonghan personality who just bottom up everything he feel and oh course someday he will explode. The explode cause they breakup, but still no explanation about how he really feel, they never really have properly conversation and that make they relationship and love for each other for years look like nothing. That came Gyu-tae in the picture, who can give what Jeonghan really want. Affection and confidence in relationship that he can't get from Kangwoo. Oh course i can see that coming, he will develop feeling for Gyu-tae. But i don't really sure what feeling Gyu-tae have. I'm still feel sorry for Kangwoo who don't really aware what he did to Jeonghan. And get dumped with kind of excuse that i really hate the most "because i really love you, so i let you go". WTF?!! And when they finally have serious talk and he know what his partner feel and try to be better but Jeonghan don't give him second chance, It's break my heart.
