a fly will not get into a closed mouth

a fly will not get into a closed mouth

proverb If you say nothing at all, then you can't say anything embarrassing or inappropriate. A: "Oh my god, I can't believe I said that. Why are you being so quiet?" B: "Because a fly will not get into a closed mouth!" Knowing that I would inevitably say something ridiculous, I kept my mouth shut—a fly will not get into a closed mouth, after all.
See also: closed, fly, get, mouth, not, will
Farlex Dictionary of Idioms.
See also:
  • a closed mouth gathers no feet
  • say
  • (I) can't say as I do(, can't say as I don't)
  • you can't run with the hare and hunt with the hounds
  • can't do anything with
  • can't do anything with (someone or something)
  • if you can't beat 'em
  • you can run, but you can't hide
  • have the gall to (do something)
  • have the gall to do