The Little Bather (1968)

Louis-Philippe Fourchaume, another typical lead-role for French comedy superstar Louis de Funès, is the dictatorial CEO of a French company which designs and produces sail yachts, and fires in yet another tantrum his designer André Castagnier, not realizing that man is his only chance to land a vital contract with the Italian magnate Marcello Cacciaperotti. So he has to find him at his extremely rural birthplace in 'la France profonde', which proves a torturous odyssey for the spoiled rich man; when he does get there his torment is far from over: the country bumpkin refuses to resume his slavish position now the shoe is on the other foot, so Fourchaume is dragged along in the boorish family life, and at times unable to control his temper, which may cost him more credit then he painstakingly builds up...

Source: TMDb