Graham Greene's Our Man in Havana is filled with interesting, and often quite dysfunctional, relationships. Before the story even begins, protagonist James Wormold's wife has left him. Apparently, that was one relationship that didn't work out. But Wormold's teenage daughter, Milly, still lives with him, and she seems to enjoy two things in particular: manipulating her father and buying things. Wormold can't keep up with Milly's desires (and fails to have any sort of discipline with regard to her), so he decides to supplement his job as a vacuum cleaner salesman by becoming a spy for England's MI6 secret service.
Wormold isn't a particularly good spy, nor is he an honest one. He makes things up as he goes along, fooling his superiors with fabricated, fantastic reports. This is certainly not a good way to build a trusting, effective employee–employer relationship! Wormold, however, carries his stories even further, describing a secret military installation based on a vacuum cleaner.
The dysfunction continues as MI6 sends Beatrice Severn to be Wormold's secretary. Wormold now has to work extra hard to keep her in the dark about his fictitious reports. At the same time, he begins to fall in love with Beatrice, and eventually, toward the end of the novel, he confesses his misdeeds to her. Beatrice has developed feelings for Wormold as well, but she still reports him to MI6 out of loyalty to her government. Wormold understands, though, and MI6 actually gives him a teaching position in its training department. Since he won't be in prison (as he thought), he asks Beatrice to marry him, and she agrees.
Things even turn out well for Milly. She has had a suitor of her own, Captain Segura, but she loses interest in him rather quickly (not a deep and meaningful relationship there!) when her father's new income allows her to go to school in Switzerland.