Tbh, this made me cry. It was really good.
(Spoilers below, my thoughts abt them)
No one was at fault, they just misunderstood each other. Jinwoo still loved Suhyeok, Suhyeok just didn't feel it. He didn't feel/think that Jinwoo still loved him. Jinwoo saw his doings, he didn't give/put enough time in their relationship. He still loved Suhyeok, he just didn't have time. At the end, they get back together and seemed better than before. Even if Suhyeok still questioned if they would still end up parting, we can assure that they're back and look happier and in a healthier relationship than they were before. I know a lot want to see what happens more in the future, if they're still together but I'm sure they are. They have finally understood each other <3
This Ending