Vatican II on Marriage and the Family
Through this union they experience the meaning of their oneness and attain to it with growing perfection day by day. As a mutual gift of two persons, this intimate union and the good of the children impose total fidelity on the spouses and argue for an unbreakable oneness between them.
Pius XII on Pleasure
The same Creator, Who in His bounty and wisdom willed to make use of the work of man and woman, by uniting them in matrimony, for the preservation and propagation of the human race, has also decreed that in this function the parties should experience pleasure and happiness of body and spirit. Husband and wife, therefore, by seeking and enjoying this pleasure do no wrong whatever. They accept what the Creator has destined for them.