Their falling out probably had to do with the third friend, Jaewon?

He was probably the guy mc saw ml with, the one he said looks like haeyool. Also, they were mutually attracted to each other when they were young but for some fucked up reason ml went for his non-blood related cousin instead. But ml's ducked upness is so hot

Edit: dropping this for now bc I cant live for ongoing series. I wish we had more works from author bc the art is so pretty