Explain the relationship between Dunstan,Boy and Leola?

This is a pretty complicated question. The dynamic between these characters certainly changes over time. By part 4, Boy wants to humiliate and rid himself of his wife. Boy is relying on Dunstan's attraction to Leola a very long time ago. There is a very unhealthy dynamic going on between the three of them with Leola as the tragic victim. One day, Boy gives Dunstan a role of film to develop; it contains several nude shots of Leola. Confused, Dunstan worries this is a sick joke, or a subtle message that Boy wants Dunstan to take her off his hands. When the situation grows weirder - Boy tries to examine the photos with Leola in the room. Dunstan tells him the story of Gyges and King Candaules, a myth in which King Candaules asks his friend Gyges to examine the queen naked. Gyges and the queen then either murder or depose the king, based on the version of the story. Boy is not amused by the story, though nine months later, Leola gives birth to a baby boy named David. Dunstan later speculates that the conception happened that night, as an expression of Boy's unease with the possibility of being cuckolded.