Binding people with wedding thread in the name of love, family (hereditary nasty lineage practice by force) exuding punishment to noncompliance thankyou i REJECT
After watching ch-30 i don't think it's his boyfriend, the ghost was worn a high school shirt which probably gives hint that the ghost was his crush/rival in the school.
They should go to the shaman (but i know the ml doesn't want to exorcise the ghost thinking it was his boyfriend)
Meow meow meow meow meowmeow meow meowmeow meowmeow meow meow meow meow meowmeow meow meow meow meow meow
MEOW!!? meeeoowww