An antiquated expression generally meaning "oops" or "whoops". This is used almost exclusively by nerds and gay men, especially when executing a clumsy or cloddish movement such as falling over a chair or slipping on an icy walkway.
While clumsily attempting to ice skate a real tool slips and falls, and when his butt contacts with the ice he yells out "whoopsie daisies!"
by KImCobain March 03, 2015
When you are having sexual intercourse with another person then admit to having multiple STDs and shout "whoopsie daisies" and refuse to pull out.
"I have herpies, aids, and genital warts WHOOPSIE DAISIES"
by Cannon Joe November 17, 2013