Communicating with a calm reassuring voice and relaxed body language, even in the center of a verbal storm created by the infidel.
I just wanted to say that as a woman, this one is huge. If you speak to her in a hateful manner, she will be running the complete opposite direction. You need to put your foot down and tell her it's a dealbreaker somehow but not in a fickle way, if that somehow makes sense. How long has the A been going on? Did she come out and tell you directly or you found out on your own? Sorry to hear you are having this problem in your M.