Military blues...:(

My bf has been wanting to go into the Air Force for a very long time we have been together for about a year. His mom hates the idea of the military and they've talked about it before she has called him stupid and an idiot because he wants to go in. He is set on going and she found out from someone else so now she is upset told him she isn't proud of him and that he ruined their relationship and she says that he picked my family over his because my family has military men and women in it. He came to my stepfather for advice because he didn't have family support. She is telling him I'm no longer allowed on their property and I just don't know what to do.. He is so upset and I'm afraid she'll kick him out and tell him to stop seeing me. I just want things to go right for him and for them to come to his graduation. Any advice will be greatly appreciated..