
i think because she didnt tell him the real reason why she broke up with him, he doesnt understand that what he's doing is actually hurtful. Things like asking to stay friends and trying to reconnect just confuses Yumin, but i doubt he has any romantic feeling behind it. I think he just sees her as family and doesnt want to lose her as a friend.
Also i REALLY hope they dont try to get Yumin's ex and Hyundo's ex together. That would just leave a sour taste in my mouth...