The Nanny - S03E09 - "The Two Mrs. Sheffields"
Fran scuffles with a woman while purchasing flowers to welcome Maxwell's mother who is visiting. The woman later arrives at the Sheffield house where Fran learns she is Mrs. Sheffield! Mrs. Sheffield annoys everyone in the house except for C.C., who right away tells her that Fran has her eye on Maxwell. Mrs. Sheffield tells his son to fire the nanny, but Maxwell proposes to Fran instead just to provoke his mother. When Fran realizes the proposal isn't real, she decides to toy with Mr. Sheffield and make him feel guilty for the insincere proposal.