The Mating Season (1951)

Director: Mitchell Leisen
Cast: Gene Tierney, Gladys Hurlbut, James Lorimer, Jan Sterling, John Lund, Larry Keating, Miriam Hopkins, Thelma Ritter

Synopsis:

Ellen McNulty leaves her New Jersey hamburger stand and heads west to pay a surprise visit to her son and his new bride. When Ellen arrives, her daughter-in-law mistakes her for the maid she has hired for a big party they are throwing. Rather than cause any embarrassment, Ellen goes along with the charade, which leads to many complications.