What do you think my old friend's girlfriend's motives are?

A couple years ago I made this really good friend. He and I got a long really well. I have a boyfriend, he has a girlfriend, both serious relationships. We were never inappropriate with our actions or conversations and talked/hung out once a month or two. A year ago I got a txt from him saying that he couldn’t be friends with me anymore because our friendship was ruining his relationship and that his girl was jealous of me and not trusting. It was funny because in the beginning of our friendship she and I would talk a lot and get along, and one day she deleted me off Myspace.

I never heard from him since. This morning, I got a message from her on Facebook as if we were old long lost friends. My response, “I thought you hated me?” She said that she never hated me and that her boyfriend wasn’t being truthful and lied a lot. They got in arguments and one day he stopped talking to me and she never asked him why, she just dropped it.

If she thought I was threatening to her relationship, why would she find me on Facebook (we have no mutual friends) and contact me? They’re still together by the way.