- what's the situation and context?

- if you are all sitting together with your children and eating a meal, be respectful of your children and bite your tongue.

- if you're just alone together and she does something to piss you off, don't bite your tongue, let her know that her crap behavior is not appreciated or wanted.

- is she still seeing the OM? If so, kick her ass out of the house. tell her she can live with him if she wants because she isn't going to enjoy the benefit of living with you while that crap is going on!