What metaphors are used in Mercy by Jodi Picoult?

In Chapter Nine, Cam thinks about the first time he made love to Allie, and how he discovered she had been a virgin. Their first time together had been traumatic to Allie and made Cam feel guilty for not paying more attention to her. The story is a metaphor to Cam and Allie's relationship now. Cam did not pay enough attention to Allie to realize that she was in pain. Cam still does not pay enough attention to Allie to see that she is growing as a person and pulling away from him, while she still loves him more than he will ever love her. Perhaps if Cam were aware of the changes in Allie he might not be so obsessed with Mia.