I would be stunned if that were the case -- it sounds 1950s vintage to me.
Wikipedia says "popularized" and points to two earlier uses (in a '60s movie and a song from the '90s). Deep 'net research.
That's what research assistants are for.
or to do a little more work, this from a 1994 Usenet post (47 instances of the phrase show up pre-2000).
But it is possible there would be those who
would be constrained, because of irony deficit, to take me
seriously, or who would find behind my choice of humor
a serious and direct pupose ("kidding on the square"
being the ancient, and very succinct, term).[emphasis added]
And via Google books (325 hits), I get a small fragment from the Random House Historical Dictionary of American Slang, which appears to have a reference as early as 1907.
I, too, would like to know the vintage and origin of this phrase, and will try to remember to pursue the question in my various phrase dictionaries when I am in my office tomorrow.
OT:
I assume that everyone here has seen the anti-proposition 8 musical?
I think when Franken uses it in Rush Limbaugh is a Big Fat Idiot he claims to be inventing it. Let me check.
I believe I actually own the Tsunami single in question (circa 1994). I know I have the compilation it's on -- you could probably even email Jenny Toomey and ask her whether it's, e.g., something one of her grandparents said.
"Soldiers assassinate Guinea-Bissau president, bomb kills rival'
says yahoo news
i laughed though i shouldn't