I think its only fair to consider limiting contact if at all. You said yourself you may have been in a relationship with her if you were not committed so to me that means that your girlfriend is the only thing standing in your way. I am a believe in fate. I do not mean that God made fate but I believe in some cosmic sense two people can be tied together for whatever reason. I do not know if it is fair to your current girlfriend because at the very least you are emotionally intimate with the friend. I am not the jealous type at all but I could see myself being bothered if my husband or boyfriend has that sort of relationship with another woman-one who used to be very tight with my partner. I think being straightforward is the way to go. You may be risking the friendship but it sounds like you are in the friends but almost more than friends zone. I dont know maybe I am wrong but I think if youre being honest with yourself it might be true. Does she have a boyfriend?