Marriage is an intimate, lifelong partnership in which husbands and wives give and receive love unselfishly. The sexual relationship expresses their married love and shows what it means to become “one body” (Genesis 2:24) and “one flesh” (Mark 10:8, Matthew 19:6). The sexual union is meant to express the full meaning of a couple’s love, its power to bind them together “the unitive aspect of marriage “and “its openness to new life” the procreative aspect.