I don't know whether she is flirting with me or just annoyed?

today i was talking to the chick i like and the only way i can flirt with her with out making it obvious that i like her is to sort of pick on her (jokeingly of cource) and she started hitting me and i don't know if this is counted as flirting back or just her getting anoyed and if its her getting anoyed then please for christs sakes how can i flirt with her with out bringing attention to the fact that i like her