Some Catholic theologians are proposing a re-think:
Lawler and Risch say their proposal reflects Catholic tradition. They noted that in the 13th and 14th centuries couples were often first betrothed — a mutual consent to spend the rest of their lives together — before they were actually married. "The first sexual intercourse between the spouses usually followed the betrothal — a fact of the Catholic tradition that has been obscured by the now-taken-for-granted sequence of wedding, marriage, sexual intercourse," Lawler and Risch wrote.
They called for a modern-day betrothal, marked by a public ceremony in which the man and woman agree to marry in the future. Then the couple could live together and have sexual relations if they chose. Then the couple would marry. This process would bring the Catholic Church more in line with today’s social norms, Lawler and Risch wrote, saying about 5 million unmarried couples already live together in the United States.
The usual objection about the "intrinsic evil of fornication" followed. But it makes a lot of sense to me.