Lovers and Other Strangers (1970)

As Mike and Susan prepare to walk down the aisle, the groom gets a case of cold feet. But turning to friends and family for support could send the couple running for matrimonial cover! Susan's father is fooling around with her mother's best friend; Mike's brother is divorcing his high-school sweetheart, and his parents are living a loveless lie. The rocky road to happily-ever-after has never been so uproarious as in this "vividly real, genuinely funny movie" (Leonard Maltin).