As a Catholic, I feel compelled to defend the position (if anyone wants more information on this view, feel free to PM me.) The Church doesn't just teach chastity and virginity until marriage to scare people or make sex out to be a bad thing. Its teaching on sexuality gives both sex and the people involved a much greater value. It defends people from being used just for their bodies.
Ahh... I know I could just write paragraphs, but I'd rather not unless anyone is interested.