Artificial contraception is a virtual necessity for the fornicator, and it has unpleasant side effects. Artificial contraception is condemned by scripture, as well as the Church, and it must be backed up by abortion. Again, we are into murder. P.S. I and II at the end of my letter. You've got to be kidding.
Scandal is a terrible thing, and again, roundly condemned by scripture.
Consider, too, the question of reputation. Suppose, as is fairly likely, your relationship breaks up before marriage. Even flaming liberals can appreciate the charm of innocence-and choose it. True love is jealous, and rightly so. This is why good priests are so desperately needed.