An observational comment unwittingly providing a woman ammunition to harass her man.
Man to clerk: ...and a pack of Camels, please.
Clerk to man: Here ya go...You know those are gonna kill ya, right?
Man's wife: Ya, see? Even he knows! I keep telling you to quit! BLAH BLAH Blah blah blah.
Man to clerk: Thanks for the nag fuel, asshole.