You could also be charged for causing a disturbance, for an indecent exhibition, obscene display or public nudity.
In Canada, it is legal for police to cruise you, then charge you. Cops have come on to men in public washrooms by rubbing themselves. Men who respond are charged. Cops have even charged men who have touched them with sexual assault. If you are caught by police, be polite and don't fight even if they are rude.