I hear ya moto. Im 19 in college, and I just am not the type of person that looks for casual relationships. One of the reasons that I feel so strongly that I can remain with my girlfriend for the long haul is because I have met many many other girls in college, but they all become friends very quickly. I have never had the slightest feelings of anything more than friendship since I have been with my girlfriend, and that is just the way things are for me.

In this situation I would suggest doing as you are and just hanging back a bit. It is tough for a girl when she still has feelings for an ex, and you should let her sort that out without feeling she is being pressured into another relationship. I promise you that in the end she will appreciate it very much, and it will be the best decision you could make.