In Paris, Bobby Summers and Mabel Mannering frequently address their Uncle Brab with the catchphrase, "Yes, uncle!". Bobby is trying to help his friend, the artist George Stark, to disentangle his amatory affairs, and for that purpose, Bobby is temporarily impersonating George, with Mabel pretending to be Mrs. Stark.
The couple have a quarrel about whether to attend the Four Arts Ball, and Bobby goes on his own, disguised as a French count, in which guise he successfully deceives both Mabel and an old flame, Lolita. Lolita successfully makes a play for rich Uncle Brab.
References
^"Chu Chin Chow", Victoria and Albert Museum, accessed 22 October 2011