Not only is this more polite, Miss Manners assures you, but if you are truly an expert in any given field, waiting it out ...

A woman, two men and a child were injured during a shooting in East Harlem late Thursday at what appeared to be an outdoor barbecue, according to NYPD officials. The gunfire erupted just before 9 p.m.

Miss Manners therefore suggests that you turn that weak smile into something that does, in fact, betray your irritation, perhaps with a murmured “Not funny.” Anything less seems only to encourage him.