Sexual intercourse between a husband and wife is a holy expression of the sacrament itself and a reflection of the love of Christ for His Church. It is where the contract is transformed into a covenant. Sex is a renewal of their wedding vows and is a physical expression of the mystery of the two becoming one flesh. “Sexual intercourse in marriage should likewise be a renewal of the covenant the couple first made as they exchanged their promises to be faithful to each other under all circumstances. When they commune with each other in this way they can once again renew their pledge, their covenant, to take each other completely, regardless of the consequences.” Sex is the martial embrace where “the words of the weddings vows become flesh.” At their wedding they take vows of fidelity, indissolubility, and openness to children, then on their wedding night they perfect, complete, and renew these vows with their bodies as they consummate their marriage.
Marriage itself has dual purposes of life and love. Sexual intercourse if to be life-giving and complete must have both these dimensions. It must be both unitive and procreative. To have one without the other would be in direct opposition to love and an affront to the meaning of sex. It would not be communicating that of which it was intended. The couple would not be giving totally of themselves and would lack the openness to life and to the one flesh union between husband and wife. In addition, it would not be a model and reflection of Christ’s love for His Church, but rather an abomination and a violation of the natural order.
 Kippley, 80.
 West, 20.