She's playing head games with you, dude. There are so many nice girls out there, girls who are honest and straight-forward and trustworthy. I think you are absolutely right that she's stringing you along to show off to her friends and maybe also to boost her own ego. If you continue to play along, and keep begging for her attention, you will teach her that it's okay to treat men like fashion accessories. There is no future with a girl like this. As soon as another guy comes along who catches her eye, she will ignore you and if you're too emotionally invested, you will be hurt. Wouldn't you rather wait a little bit longer until you find a girl who treats you like an important person?