Most Helpful Girl
I think she's playing with you and she's just keep you around as a rebound for when her relationship with her boyfriend is actually over and done with.
Most Helpful Guy
Be careful with this. Lots of girls flirt for solely for attention and validation, and these are the women that really screw with guys' heads.
TBH, it sounds like this girl is strictly playing around with you. Any time a girl acts this way and then turns out to have a boyfriend, I forget her name very quickly.