Sir? In public? Oh come now. I am sorry, i totally disagree with what everyone else has stated. If you're respectful toward him in public... shouldn't that be sufficient enough? ~sighs heavily~

Reprimanding you in public is, to me, just wrong... (unless of course you've already agreed upon it). A subtle look should suffice.. if your misbehavior continues, a more blatant gesture... both should warn you that you have displeased and will be corrected once behind closed doors.

Just my opinion.