The Astonished Heart (movie, 1950)

Several years after graduation, best friends Barbara (Celia Johnson) and Leonora (Margaret Leighton) reconnect as if not a day has gone by. But Leonora could do without Barbara's husband, Christian (Noel Coward), whom she finds arrogant and off-putting ... at first. One evening alone together, romance is set ablaze, leaving Christian with a lot of explaining to do to Barbara.