Sex is not merely some recreational activity designed for human pleasure. St. Paul tells us that when husband and wife come together as one flesh, the language of their bodies is a “great mystery” that is meant to prophesy to the world the union between Christ and the Church. Therefore:
Both husband and wife should be fully aware of the sanctity of the marriage bed. It must always serve as a means to grow in mutual love. And it should be kept pure on account of the great reverence they bear for the sacrament that blessed their union.