The Grass Is Greener [1960, UK, comedy, DVD5]

Married for twelve years with two adolescent children, the Earl and Countess Rhyall - Victor and Hilary - live in a small section of the country manor that has been in Victor's family for generations, the rest of the manor having been turned over to the National Trust for public tours, the only way they, cash strapped, can keep the property as a legacy for the children. In addition to Hilary's side business of growing and selling mushrooms for her own pocket money, they don't live a typical royal life in not utilizing their servants to their fullest, with especially their butler, Sellers, who only sought out the job for experience to write his "great British novel", telling Victor either to fire him or reduce his wages in feeling he having nothing to do. Victor counters that especially Sellers provides the important function of the facade to the public, who pay for the tours, of true royal country manor life. Their life is turned upside down when American oil baron Charles Delacro takes the tour, and meets and falls immediately in love with Hilary. While she initially rebuffs his advances, she eventually does return his affections. In meeting Charles, Victor knows that there are feelings between Charles and Hilary, and that Hilary's extended trip to London, in which she will be staying with their socialite friend Hattie Durant, is just a guise to have an affair with Charles. With Hattie being his confidante despite their outward animosity in being former lovers themselves and with Sellers doing his butlering duties, Victor goes on a mission for Hilary to return emotionally in love with him.