So my situation is this: The girl just got out of a 5 year relationship a couple months ago, and since then we've been fooling around. I'm not "the rebound guy" because there was another one in between us. We've known each other for a few years and there's always been attraction between us, but we both were otherwise involved. Now we've been going on dates and we had a couple nights of fantastic sex, but she's still wanting to play the field a bit before she settles into anything more serious. She's explained to me that she's not looking to sleep around, and that since she broke up with her ex, she's hung out/gone on dates with several people, but that she's only slept with me. she also has repeatedly gone out of her way to tell me that if she was ready for a new relationship, that it would probably be with me. On the other hand, when guys approach her in bars or whatever, she tells them that she's single, and has given her number to a couple of them. She's never lied to me about it, she's very honest and straight-forward.
I've been cool about the whole thing, but I'm not sure if she's just testing me, just using me for sex, or if she legitimately feels this way. In any of those scenarios, how do I move this forward?