In my view, the video below (from the Vortex with Michael Voris) shows the importance of the Catholic Church's teaching for chaste marital relations without contraception. Contraception stifles grace since it doesn't allow for the married couple to participate in God's Will of creation in their vocation. Stifling God's Will potentially, if not necessarily stifles His Grace.
I thought that marriage showed how Christ's love for His Church was present, but the oneness between Christ and His Church was really preeminent to marital love. In other words, if there was no fall, there would be a perfect oneness between Christ and His Church; it's just that the fall caused humanity to have to be re-grafted onto Christ through baptism, or through the remission of sin/reconciliation with God.
WARNING: the subject below may be too graphic for sensitive readers.
Finally, I thought of a few analogies that went with the use of contraption vis-a-vis receiving Holy Eucharist (stay tuned for a question for you):
(1) Condoms: putting a barrier around Holy Eucharist
(2) The Pill: taking a drug that put up a chemical barrier on the absorbing wall of stomach/intestines/esophagus so that Holy Eucharist could not become one with the Communicant
(3) Diaphragm: Putting a hollow balloon in one's mouth
What analogy do you think works for homosexual relations? Please comment below.