Almost 30 Years later - I finally get it.
NO FLIES ON YOU. In season one there was a recurring joke in (I believe) the pilot episode and someone said ... No Flies on you.
Later it was repeated to David and David turned to the camera and said "Someone has to tell me what that means.
I originally thought it meant "What you are saying is not BS" because flies are attacked to Sh** .... and that still might apply. Example: Instead of say "No Sh**", you would say "No Flies on you".
But me and a friend were taking about Democrats and republicans and how you can "catch more flies with honey". She went on to say " ... people need to learn to be a little nicer" ... and in the same breath started reprimanding our waiter for not paying attention to how she wanted her salad.
As the waiter left, I said ... "No flies on you" ...we both burst out laughing and I told her about the Moonlighting episode.
Do you agree?