How do i tell her this?

I'm a girl and been dating my girlfriend for 2 months already. I look like a guy (having small boobs, short hair, etc). She thinks I'm a guy. She tried grinding on me at clubs but I pushed her away. She really wants to kiss me. I want to too but I fear she want to break up with me. She's straight. I don't want to hurt her. How do I overcome my fear to telling her that I'm a girl?How do i tell her this?
r u afraid she myte leave u? if yes luk at the situation from dis point that even if u dnt tel her dat ur a girl she would come to no dat one day or anoder probably when she's trying to turn u on r she myte get 2 no abt it from sum1 else(which is horrible)... so d only way u can feel better is just tel her that u r sum1 whom she myte not lyk 2 hang around wid. if she doesn mind u being a girl it seems u r luky or just try behaving more lyk a girl so that u gt hold of a boy next tym. and yes wat r u afraid of? she wont gobble u dwn if u told her wat u were. just b happy wid wat cums ur way and yeah if she leaves u then u shud undrstand that one of the reasons 4 hvin a troubled lyf just walked out of ur path....How do i tell her this?
wow that's disgusting you should step out of her life immediately you perv
Wow, your in a tight situation. Are you bi??? Or are you just confused....