This was the last film that Jerry Lewis made for Paramount Pictures, marking the end of a 17-year association.
A dispute over which actor--Tony Curtis or Jerry Lewis--would receive top billing was settled in print ads and posters by criss-crossing names on a diagonal so a portion of each star's name on the top line appeared on the top line (first name for one, surname for the other--with remainder of name on bottom line in reversed order.) In the film's trailer both names flash on screen in an animated circle, rotating so rapidly it's impossible to discern who is the top-billed star.
Jerry Lewis almost co-stared with Tony Curtis in Some Like It Hot (1959) as Jerry/Daphne but declined because he didn't want to dress in drag.
The French play upon which this movie was based ran for ten years in Paris and over six years in London, making its author, Marc Camoletti, a millionaire; but it clocked up only 23 performances in its original New York Broadway run in 1965. A New York revival of over forty years later was more successful, running 279 performances and winning several Tony awards.