For all you gay/bi/lesbian need advice ?

I have a couple of bi friends and they just happen to be one of my best friends. And they also just happen to be girls which can be awkward on my behalf because I'm a girl. Since I have a lot of Bi friends even though I myself am straight I'm rarely awkward around them. As a matter a fact I never am except with one of my friends because she makes passes at me like she slaps my but and tells me how pretty I am and one time when we went to the amusement park and my hair get wet she was " you look so sexy with your hair wet". she pretty wild and outgoing and she plays a lot but she only does this to me and she knows I'm straight she's asked before. And i get real mad when she does these things and sometimes she acts like I'm acting weird what should I do ?