A Letter to Three Wives (1985)

Three women are going on a trip that leaves them incommunicado with the rest of the world, but before they leave, a woman who either has a history or relationship with each of their husbands leaves them a letter that says that she is leaving with one of them. As they wait to return so they can find out who it is, they each remember an important moment in their lives that involves all of the players in this sordid affair.