It's like both of them trying to keep suha as their pet although the way they act to suha is different. Also I think park is scared of redhead and that could be the reason why he keeps suha at home.
I'm just imaging their older versions. Both of them at hospital, Kirin just turns off Moo's life support saying "told you I was gonna kill you". That would make me chuckle. Moo's condition sucks though. Maybe put him into death game he'll win for sure.
FBI OPEN UP