I've been on that very same situation as well, and after an open conversation about it and a clear statement from both on how we felt about it, friendship it was set to be. And honestly, that was the best choice. With a commitment you get a whole set of, lets say, responsabilities that sort of take the fun out of it. Think: apart from sex, what are the advantages? Closeness? Can't you have it with a friend? I talk openly with my friends, I love them the same way, and I don't feel such an urgency to live on the same place or sleep in the same bed as them. And if you are taking sex as a priority here, then you should re-think how you see a relationship... Well I could be wrong, though, and this could be the result of my way of dealing with relationships and being a closeted asexual (don't worry, not as George Takei USED to be). But this is how I feel about it. What I'm saying is: if you haven't spoken about how you feel with her, DO so. You will NOT lose her respect or her friendship - unless you say something stupid like "Hey, wanna do it?". If she's not up to it, well, it was NOT meant to be. She will be there for you, though, and will be very close to you, even more than in a relationship because there is no pressure on satisfying the other or keeping an "image". You can truly be yourself, you can do what you want, you can hang out with who you want... And when it's meant to be, both will know, and both will be willing to do that extra step. So relax and welcome to the human race, filled with pains and sorrow and problems that make the rest of our life look so wonderful in comparison!