et semel emissum volat irrevocabile verbum

[randomness]

(and a word once uttered flies abroad never to be recalled" [Horace)]

or, to repurpose something parallel I've heard attributed to browngirl:

"That which is said cannot be unsaid."

But it's better to know than not, eh?

Thanks to dpolicar for the Latin expression.

Comments

[bikergeek.livejournal.com]

Actually the "Winged words" thing dates to Homer, from the Odyssey.

In legal contexts, the metaphor "you cannot unring a bell" is often used, as I understand it. (I.e. a jury cannot unhear information they've heard. If a judge orders, "The jury will disregard that comment/question/answer," that doesn't really work.