a slanging match
A bitter argument or dispute in which each side hurls numerous insults, accusations, or verbal abuse at one another. Primarily heard in UK. At first, I thought we were just going through a rough patch in our relationship, but lately, it seems like every night Janet and I get into a slanging match with each other. It might be time to end things.
a ˈslanging match(British English, informal) a noisy, angry argument: It started as a peaceful discussion, but it ended in a real slanging match.
Slanging in this idiom comes from the old verb slang, meaning ‘to attack somebody with rude and offensive language’.