What happens between Cheri and Lea in "Cheri", "The Return", and "The Pearls"?

In "Cheri", "The Return", and "The Pearls," Cheri has a love affair with Lea, a married older woman and then reveals that he is getting married. Cheri later returns to her after tiring of his wife and they run away together to Tunis and he sees her aging and becomes depressed, thinking of the wife whom he left behind.