That's how mature Hyesung is now. He could have ignored what happened before, but because he cares so much for Dojin and Byul, he took their opinions seriously and wanted to see for himself.
I think this is for the best, just talk it out so there are no hard feelings and they can move on.
(P.s i still hate his mom tho)
Sometimes i wonder why author loves to mix side couple story in the main story
Reading it back and forth between the couples makes me lose focus on the main story a little :( like, i don't mind if it just side story but the whole plot for 3 couples in 1 manga?
But, in the end i love this regardless
Is that.... hickeys???? Kyaaaa ε=ε=(ノ≧∇≦)ノ