Thank you for bringing your question to Just Answer!
It sounds like you've gotten yourself stuck in the middle of his drama with his son's mother. I have a feeling he'll be really mad at you when he finds out you repeated what he said....because he's really not done with his relationship with her yet. The fact that he cheated on you with her shows how much he's still tied to her.
If you hope to make a life with this guy, you'll have to work hard to stay out of anything to do with his ex. Hoping that she'll cut him out of her life when she hears what he said will probably back-fire. He'll deny it to her, and accuse you of being a liar.
" She confronted him and told her to get a life"
Do you mean she told him to get a life, or was it the other way around?