Don't Let the Angels Fall (1969)

Robert, a Canadian businessman depressed by a sense of failure of his personal and professional lives, attends an insurance convention in the US and inevitably has an affair with a woman there. He returns to his family in Montreal; his cold marriage to his wife Barbara and two sons ages 19 and 13. His family life continues to disintegrate when his older son becomes romantically involved with a night-club singer who encourages him to participate in protests on his campus and his younger son, confused and insecure, skips school and dreams of running away. His wife is stuck in the middle; she suspects Robert had an affair and no longer feels adequate as a mother and wife. Robert continues to become more distant from his family and is increasingly distraught with his lack of ambition, wishing to do something that matters.