Rumpus in the Rumpus Room is the third episode of the fourth season of Maude.
This and three other episodes ("The Split", "Consenting Adults", "Maude's Big Decision") comprised a four-week story arc which centered on the possible dissolution of the Findlay marriage due to Maude's political ambition and Walter's chauvinistic tantrum concerning it.
Summary
Maude and Walter meet at a party celebrating Arthur and Vivian's first wedding anniversary. Maude comes on the arm of Senator Bob Myers, her political ally, while Walter, comes on the arm of a young woman named Cathy (Bernadette Peters) that he met at a bar. Cathy is a lovely woman, but she is not really all that bright.
Despite her attempts to meet and greet everyone, she is still angry with Walter for trying to stop her political ambitions.
Inevitably, another fight brews between the warring soon-to-be exes, where yet again, Walter relentlessly demands that she drop her bid and return to being a traditional wife to him. Maude is getting more and more irate because he is still trying to demand that she become again his wife. When she refuses to back down and give in to his blackmail, Walter immediately begins drinking again.
He and Arthur go back to his apartment building, while singing at the tops of their voices, off-key! At that point, the same tenant (again played by Stymie Beard) who insulted Maude, tells them to shut up!
An upset Maude, accompanied by Senator Bob, to check on Walter, and seeing him in bed with, whom she thinks is Cathy, but was in reality, Arthur, finally realizes that her marriage is over. She begins to accept that Walter is more interested in what he wants, and that he doesn't care about what she wants. Broken, she returns home, and then puts on a face of being care free.