Hi Maternus,
I can relate with an ex partner prompt arguments in front of family members particularly her parents, sometimes her sister and all of her family members.
We had other arguments, but she never went so far, when there was no audience. But I think she is using this incident to tell her mother ":)o you remember that night in your house, when we had that argument in your dining room? Can you imagine how brutal he was, when there was no one around to witness?"
A pwBPD will shift between all 3 roles of savior, persecutor and victim in a
karpman drama triangle.