Green’s Dictionary of Slang

(US) homosexual, effeminate.

1942		W. Winchell On Broadway 24 Jan. [synd. col.] Digging up the proof on that whoopsy columnist’s original job.
1943		W. Winchell On Broadway 4 Nov. [synd. col.] He has none of the ‘nancy’ or ‘whoopsy’ manner you’d expect.
1952		W. Winchell ‘On Broadway’ 8 Aug. [synd. col.] A raid on a whoopsy dive.