Evening (2007)

As Constance (Natasha Richardson) and Nina (Toni Collette) gather at the deathbed of their mother, Ann (Vanessa Redgrave), they learn for the first time that their mother lived an entire other lifetime during one evening 50 years ago. In vivid flashbacks, the young Ann (Claire Daines) spends one night with a man named Harris (Patrick Wilson), who was the love of her life.