 As a practical joke, during the scene where  William Holden (I) (qv) and Nancy Olson (qv) kiss for the first  time, Billy Wilder (qv) let them carry on for minutes without  yelling cut (hed already gotten the shot he needed on the first  take). Eventually it wasnt Wilder who shouted "Cut!" but Holdens  wife, who happened to be onset that day.