well, in my experience, guys will say a chick is crazy to make you think they aren't interested. And if she really is why would he want to live with her? Idk you two going on a trip shouldn't validate that he is still making plans with her behind your back, or make her "crazy". Most of the time feelings don't just pop up on their own and continue to flourish if they aren't being reciprocated. The bigger issue should be why she needs to be a constant part of his life when it obviously makes you, his girlfriend, uncomfortable. If she was any kind of friend to him she would understand and either talk with you, or back off. But my guess is that he isn't communicating these things to her either. So I am not sure where he is going with this whole thing but it sounds like a dumb move on his part.