What he does or appears to be doing inside his pants is the public's business if he is in public view while doing it. Even in CA. In CA it falls under PC 647(a), Lewd or dissolute conduct in any public place or in any place open to the public or exposed to public view. Nothing has to be exposed, you just have to be touching (or appearing to touch) your "private parts" (or someone else's) for the purpose of either sexual gratification or to offend someone else. It would appear that FL has a similar law.