I would set a boundary that she cannot call or text him in the house or around the children.
I would be very firm on that.
Myself. I set the boundary that if I caught her doing it in the house or around me. She would have to leave the home. As the home had suffered enough disrespect from her actions.
As it was her work phone I had no control over that. But if it was a phone I paid for. I would have cancelled the phone as well.
Yes I kept my boundary.
I would suggest the same thing, I DID the same thing, and my wife did respect the boundary. There's no reason why you should allow her to do this right in front of you.