Today’s morning name, but it comes with crucial context. The Don’t ask! in question is not the neutral use of the negative imperative, advising the addressee not to ask someone about something (Don’t ask them about the ducks in the kitchen; that just makes them crazy), but instead is a formula of Yiddish-influenced English, normally used only by (American) Jews (or gentiles culturally close to this community), when someone has in fact just asked about the matter in question (the tsuris / tsores ‘troubles’); the speaker doesn’t go on to avoid this sensitive matter, but instead embraces it, launching into kvetching ‘complaining’ about it.
The formula Don’t ask! then serves as an announcement — a kind of alarm bell, if you will — that the speaker is about to go off on a (perhaps extended) kvetch.
