In both this class and Family Foundations, we have been discussing the sacred nature of sexual relations between husband and wife. Don't misunderstand me - the classes haven't been raunchy or anything - we have focused more on the relationship aspect, the beauty of it when done in the right context.
Like this: relationships, especially marital ones, need so much more than a good sex life. Relationships should (and are required to have if they are to last) have intellectual, spiritual, non-sexual physical, and emotional bonds. All of these build intimacy, fulfill God's commandment to become one, and make the physical intimacy aspect more fulling, more meaningful. It is the symbol of the bonds of all other aspects of intimacy.