A primary theme of the novel is coming-of-age, particularly as it pertains to sex and sexuality. Susie’s death occurs shortly after her first kiss, and she loses her virginity when Harvey rapes her. Susie’s sudden death denies her the experience of many coming-of-age moments, and her only sexual encounter is colored with pain, violence, and death. Susie can only vicariously enjoy crucial cornerstones as she watches her sister Lindsey grow up while Susie herself remains stuck in time. Susie watches Lindsey have her first kiss, lose her virginity, graduate high school and university, become married, and finally become a mother herself. At the climax of the novel, Susie is finally able to experience sex with Ray Singh, which she has always desired during her time in heaven. In contrast to her violent rape, her experience with Ray is tender and loving. Susie is then able to accept her death and move on to the true Heaven.

The novel also contrasts sexual experiences between the adult and youth generations. Jack and Abigail become estranged after Susie’s death, as do Ruana Singh and her husband. Similarly, Abigail stops sleeping with Jack and begins an affair with Fenerman. Abigail uses sex with Fenerman as an escape and as a willful forgetting of Susie, rather than the cultivation of a loving relationship.