Mike Vecchio and Susan Henderson are engaged to be married. Mike wants to call off the wedding, arguing that it would be hypocritical for them to get married when they’ve already been living together for a year and a half. Mike relents on calling off the wedding after learning that Susan went to her first Halloween party dressed as a bride.
Susan’s WASP-ish parents, Hal and Bernice, are experiencing their own issues, as Hal has been having an extramarital affair with Bernice’s sister, Kathy, who is afraid of ending up a spinster and is using the wedding to get some commitment from Hal. Susan’s older sister Wilma and her husband Johnny are parents of two children. Wilma is feeling her age and misses the passion they had at the beginning of their marriage, while Johnny is more interested in watching Spellbound on TV than giving his wife attention.
Mike’s brother Richie and his wife Joan have grown “incompatible” and are considering divorce. Mike’s Italian-American parents, Frank and Bea, are relentlessly trying to dissuade Richie and Joan from divorcing. Mike and Susan “fix-up” bridesmaid Brenda and usher Jerry for the wedding, and nebbishy self-imagined playboy Jerry spends most of the weekend trying to “score” with Brenda.
These stories all play out through the rehearsal, wedding, and reception.