Bisexuality Support Group
Bisexuality is a sexual orientation which refers to the aesthetic, romantic, and/or sexual attraction of individuals to other individuals of both their own and the opposite gender or sex. Most bisexuals are not equally attracted to men and women, and may even shift between states of finding either sex exclusively attractive over the course of time.
I too have a very intense long-distance telephone relationship with a straight woman who lives in Walnut Creek, and while she is my best friend I have already decided that a romantic entanglement is out of the question once she moves to LA because I don't want to ruin what is great about our friendship.
Regrettably, sometimes not going for it is the better path. If you feel it will ruin the friendship it probably will.