Danny Muldoon (John Candy), a 38-year-old Chicago Chicago Police Department, still lives with his overbearing Irish American mother, Rose Muldoon (Maureen O'Hara). A lonely bachelor, Danny falls in love with Theresa Luna (Ally Sheedy), an introverted, lonely girl who works in her father's funeral home as a cosmetician. On their first date, he takes her to Comiskey Park and has a picnic on the field. Their courtship eventually becomes very difficult because Rose begins to feel threatened that Theresa is trying to steal her son away; the fact that Theresa is not Irish (she is Sicilian American and Polish American) only exacerbates the situation.