Why is she acting like this?

Basically, I got rejected by a girl, about a year ago. Thing is we were friends before this and she used to like me too, but I guess I waited too long. Anyway, at first, it was awkward but over time we had become much more comfortable around each other again and were "friends" again. Thing is, she has told one of my (guy) friends that she thinks "I'm such a d**k". I mean I have made a couple jokes at her expense, but no different than how I tease any of my other female friends. I'm confused because she still tries and has conversations with me in cl. She basically sways back and forth, one minute she is a b***h to me, the next friendly. Literally today, she was talking to the same friend in cl about how much of a jerk I am (she thought I couldn't hear her). As a result, I essentially told her to f**k off. But, why is she acting like this all of a sudden?