Wow that sucks. Although, she probably really couldn't help it being in the through of passions and all. I doubt she did it on purpose. However it would seem that she does find this friend sexually attractive. Don't you ever fantasize about other people when you're having sex? It is a tough situation and really it comes down to how you feel about it. Does she realize that she said that? Just because she said his name doesn't necessarily mean she has feelings for him. Ask her about it. Regardless though if knowing she's attracted to this guy really bothers you, you probably aren't going to be able to let it go and should end things.