Responses
I think he started regretting it after what he did. That's why he avoided him and apologized only when het slept. Than when he ended his own life, that's probably when he realized how late he was. That he committed a grave sin to his partner. That he's truly trash
He only regretted it after their memories were shared because of bonding, he probably found out about se jin being SA'd by his fuckass brother, that's only when he started to feel bad
Idk, I'm sorry even how much present Kwon Ido changed i still feel rage inside me... Sejin's death was the only eye opener for him to treat the poor omega better.