In group therapy, a client angrily speaks up and responds to a peer, "you're always whining, and i'm getting tired of listening to you! here is the world's smallest violin playing for you." which role is the client playing?

The person in group therapy that gets angry and calls out a peer for whining and expresses that he's tired of listening to the other person is playing the part of an aggressor. If the peer that was called out takes the verbal attack without defending himself, he is playing the part of a doormat.