The sex in the film is mostly necessary because the scenes themselves raise the stakes as the healing process begins. Flashbacks further the emotional bonding between the audience and Maria, while we all watch as Joseph has trouble dealing with all of it. In possibly one of the most shocking and stunning scenes in any film I've seen, Joseph makes love to Maria and as she remembers long-forgotten memories, she convulses and shivers. Her throat closes up and Joseph calls the paramedics. It was so emotionally convincing and stimulating that I had trouble watching.
Sex is an emotional and physical process, but most films portray it as a physical act only.
The former element is what makes the film so difficult to watch, and yet you can't take your eyes from the screen. The film was written and directed by newcomer Lance Young. Young has not had much experience considering he went to college on a golf scholarship. But after making this film, Young is definitely a director to be reckoned with. His style is simple but very effective.