Im sorry to hear that. I know what your going through. I feel the same way and have the same kind of friends. Its like your there as a "back up" or the "2nd option", they ditch you if they get a better offer. My friends keep doing it, it wears you down doesn't it? Maybe tell this friend how you feel.. it wouldn't be easy, but i've made the mistake in not telling my friends, and now its too late and keeps happening. I seem to have a knack for finding people like this too....lol it can be hard to find decent friends.