I am not going to flame you, because you are here, meaning you give a damn about yourself.
however, I will point out that you do need to read the DJ bible.
First, look at it this way... You are the one presisting on seeing her, and then when she tells you that you can come and see her, you get mad because she has a BF and tell her that you don't want to talk to her.
That's being a contridicton.
What makes you think she in an AW? Because she has a BF? Mabye she is just in a F'ed up relationship. Don't be soo quick to judge. I am not say ing she isn't, because I don't know her, but with that said, I don't think you do either.
If it's sex you want or a realtionship (which I wouldn't recommend), you have to work your way up. You aren't going to come in the game being on the same level as her BF. it's idiotic and unrealistic to think that... Considering how you played it, it's a gift you even got an offer to come over her place.
Now, if you play your cards right, show her you are interested but not infactuated, show her a good time, in other words, present her with a alternative option besides her BF, then you can get somewhere.
But you or anyone else, can't expect to talk to a girl with a BF, and then from jump street be on the same level as her current BF, it just doesn't work like that.
As far as how you played it, you aready messed up, she is already looking at you like "WTF? did I do wrong?". Just chalk it up to experience. If you see her, don't be mean. Be flirty and let her make the move in this case because as bad as you messed that up, it would only get worse if you called back apologizing.