friv....hey, that is great insight bro, just add to this....
a lot of times, men adn women who have been sleeping wit each other, sex partners for a while, or whatever, could be looked at in the public eye as a couple, but if you asked one or the other, they would boldly say, I am single!
This puts a lot of pressure on the two parties, because they want to continue seeing each other, but they dont want to hurt each other in the long run, because of the friendship they contain..
School buddy, what you have is a girl you care about, more as a friend than as a lover, and perhaps your fear of being her lover, will destroy your friendship......
well, best route you could take, is just when she wants to become a couple, just say, in a joking way, baby, we are friends! You are my girl! How would that look if we were both all serious with each other....
This is very light, and fun, and she will not see it as rejection, but you too will just continue as you are...ant that is friends, sex partners, I can tell anything to you partners, for the rest of your lives or at least, until you go your separate ways.
Tell me bro, does this help you?