Sexuality is an issue at the heart of the Christian family and God's plan for a romantic love-relationship between man and woman. In connection with this, John Piper's book, Sex and the Supremacy of Christ, is really quite special both in its scope and in its unrelenting Christ-centeredness. It is available here:
http://www.amazon.com/Sex-Supremacy-Christ-John-Piper/dp/1581346972
