Odd Obsession (1959) aka Kagi

1959

A middle-aged husband of a younger woman finds her youth intimidating to the point that he cannot become aroused. His solution involves the introduction of his daughter’s lover to his wife. An aging antique specialist in Kyoto, Japan is losing virility but finds himself excited when he deliberately makes his daughter’s boyfriend attracted to his younger beautiful wife. Things begin to spiral as his health declines and the plotted becomes the plotting.