Sex in this novel is shown as a way of communicating between two people. This is something that not only occurs between the two people involved in the act, but also between the couple and society as a whole. Lurie's various failed relationships demonstrate this. He refuses to listen to Soraya and Melanie outside of his sexual relationship with them, and therefore abuses their relationship. Of course, another important example of sexuality in the story is Lucy and her partner. Because of their homosexual relationship, they are perceived ina different way by society as their relationship does not fit the norm of sexual mores and codes.
Lucy later on views her rape as a way of her assailants expressing their repression and their power over her by marking their territory. She is therefore able to see the rape in perspective and not take it personally. Lurie, who was only able to watch this tragic event unfold from his position of an observer, being locked up, sees it differently and wants justice for his daughter and her assailants. He is unable to understand that justice is something that exists in a very different form if indeed it exists at all in this world that he is a part of.
Sex and sexuality therefore primarily concern relationships and how we communicate with each other, or fail to communicate with each other, in this novel.