Flog something to death - Idioms by The Free Dictionary
flog something to death
flog (something) to death
To linger over or discuss something so long and to such a tedious and laborious extent that the subject is no longer of any interest or relevance. I think we should move on to another topic before we flog this one to death. The film's rhetorical message has been flogged to death by everyone you talk to.
ˌflog something to ˈdeath (British English, informal) talk/write about or deal with a subject so often that there is no longer any interest in it: The word ‘new’ has really been flogged to death in advertisements, and nobody believes it any more.