An exclamation of surprised or incredulous curiosity, sometimes (but not necessarily) a literal prompt for the speaker to tell more. You're getting a divorce? Do tell!
A phrase used to express surprise about something, as in Jane's getting married again? Do tell. This expression does not necessarily ask the speaker to provide more details but merely expresses one's astonishment. [Colloquial; first half of 1800] For a synonym, see you don't say.
sent. Is that so? (A disinterested way of holding up one end of a conversation.) So, you’re a dentist. Do tell.