As hard as it might be to believe, a silent film melodrama once used a silly plot twist that would later become crucial to Laurel & Hardy's Sons of the Desert (1933). In Louis Feuillade's Tragic Error (1913), a husband goes to the movies one afternoon and sees his wife on screen in the arms of another man.
By this time, the plot had already been used in a Biograph comedy. Certainly, the idea of an untrue spouse being exposed in footage exhibited at the local theatre is good for a laugh. It is hard to believe that a filmmaker as reputable as Feuillade thought that theatergoers would take this type of plot seriously. It is no surprise, then, that the plot would be returned to the comedy makers, who would make use of it extensively for the next several decades.