Monica, there is an excellent treatise on sex written by two  non-clerical theologians: "THE SEXUAL PERSON:
Toward a Renewed Catholic Anthropology" by Todd Salzman and Michael Lawler.
"In short, say Salzman and Lawler: emphasize relationships, not acts, and recognize Christianity's historically and culturally conditioned understanding of human sexuality." http://press.georgetown.edu/book/georgetown/sexual-person