Housewife Francine Fishpaw watches her upper-middle-class family’s life crumble in their suburban Baltimore home. Her husband Elmer is a polyester-clad lout who owns an adult movie theater, causing anti-pornography protesters to picket the Fishpaws’ house. Francine’s Christian beliefs are also offended by the behavior of her children—Lu-Lu, her spoiled, promiscuous daughter, and Dexter, her delinquent, glue-sniffing son who derives pleasure from stomping on women’s feet.
Francine’s troubles are compounded by her cocaine-snorting mother La Rue, a class-conscious snob who robs her daughter blind and constantly derides her obese appearance. La Rue berates Francine for befriending her former housecleaner, Cuddles Kovinsky, a simple-minded woman who tries to console Francine with “seize-the-day” bromides and has inherited a large sum of money from a former employer.
After Francine discovers her husband is having an affair with his secretary, Sandra Sullivan, she confronts them during a motel tryst and demands a divorce. Francine then falls into alcoholism and depression, exacerbated by her children’s behavior: Lu-Lu becomes pregnant by her delinquent boyfriend Bo-Bo Belsinger (Stiv Bators) and announces she is getting an abortion, and after Dexter is arrested at a supermarket for stomping on a woman’s foot, the media reveal that he is the Baltimore Foot Stomper who has been terrorizing local women with his serial attacks.
Lu-Lu goes to a family planning clinic for an abortion, but is harassed by anti-abortion picketers. She returns home and tries to induce a miscarriage, causing Francine to call an unwed mothers’ home. Two nuns arrive, force Lu-Lu into the trunk of their car, and take her to a Catholic home for unwed mothers. La Rue is shot by Bo-Bo and his friend, who have come to trash the Fishpaw house on Halloween night. La Rue retrieves the gun and shoots Bo-Bo, killing him. After Lu-Lu flees the unwed mothers’ home, she returns home to find Bo-Bo’s dead body and is so distraught that she attempts suicide. Francine comes home and faints after witnessing her daughter’s suicide attempt—and the apparent suicide by hanging of the family dog, Bonkers, based on a suicide note left near the dog’s dangling body.
Francine’s life soon starts to change. Dexter is released from jail, having been rehabilitated. Lu-Lu suffers a miscarriage from her suicide attempt and is contrite about her past, becoming an artistic flower child who embraces macramé. Francine quits drinking, confronts and rebukes her mother, and finds new romance with Todd Tomorrow. Todd proposes marriage to an elated Francine, but she soon discovers that Todd and La Rue are romantically involved and conspiring to embezzle her divorce settlement and drive her insane.
Elmer and Sandra break into the house to murder Francine, but are killed by Dexter and Lu-Lu: Dexter steps on Sandra’s foot, causing her to accidentally shoot Elmer, and Lu-Lu uses her macramé to strangle Sandra. When Cuddles and her German chauffeur and fiancé Heintz arrive, their car runs over La Rue and Todd, killing them. The film concludes with a happy ending for Francine, her children, and newlyweds Cuddles and Heintz.