I hear my older coworkers use this idiom/phrase occasionally. It seems possibly to be a humorous way to get out of a conversation. Even as a native English speaker, I've never figured out the exact situation you would use this phrase. It almost sounds like it may have once been a punchline to a joke in a movie or something.
I'm curious what is the exact meaning/usage of this phrase/idiom? Where does it originate?
Best Answer
Wikipedia actually has an article dedicated to this phrase. It says:
Wiktionary adds:
As to the exact situation in which you would use this phrase, it suggests:
Back to Wikipedia again,
World Wide Words has additional info: