So the question you have to ask yourself now is - why? Why did you behave this way, knowing how hurtful that can be? Why did you not shut down the other girl immediately? Those are sincere questions. This type of thing has happened to me and those were the questions running through my mind. It is very difficult to understand how someone who claims to care can be so different from who you thought they were..
maybe we're both rebounding.
Incidentally, I chatted with her on facebook this evening for a long time (it is 11pm here now), and she seems to be getting more and more flirty. Teasing me about how I have so much work to do. Then saying she wished she was there so she could give me hugs. Then saying she's going to bed, and mentioning how warm her bed is, then when I flirt back, with "I'm jealous!" she sends a wink face, and another "".