If someone does something that is extremely unfair, or says something thats offensive or hurtful.
Betsy: He called me a whore!
Lisa : That's bang out of order...
145👍 14👎
British slang, it means something thats very offensive or extremely unfair.
Kid: You're a liar, Harry!
Harry: *Stomps upstairs and Ron follows him.*
Ron: That's bang out of order!
7👍 1👎