Responses
If I was the MC, I would've pulled up a chair and watched her. Like, her shameless existence is an eyesore so please go ahead and do us all a favour.
If she really did though, the only con is that she's doing it in their house, but the witnesses and evidence are there, plus I'd shift all the blame to the cheating father, who ruined two women's lives.

Mistress: let me live here or I'll kill myself
Me: ok, I'm waiting. No one that selfish will ever take their own life