How do you know when a girl is annoyed of you?

When they are annoyed they will look into your eye's and say stop it!,Don't,leav me alone,and get off when they say that don't keep doing it or they will think your flirting with them,but if you are fined out another way to flirt with them or they won't like you because you are akting like your 11 years old. Also when they say that STOP! OK