Okay, I've thought about it overnight and considered the changing 'normal' in our American culture. In my lifetime I have seen us go from a norm of only the trashiest and immoral people would live together without benefit of marriage to cohabitation before marriage being the cultural norm by something between 50 and 60%.
In the same length of time, the cultural norm has gone from 'save it for marriage' to be sure you have a condom in your purse or pocket at all times just in case. Sex before marriage no longer tars somebody as a 'playboy' or 'loose woman' and living together is no longer considered a character flaw.
The upside to all that is the vanished 'scarlet letter' and much less negative side of shame.
The downside is a huge increase in STDs, many more unwanted pregnancies and abortions, a huge increase in single parents with resulting increased negative statistics of child poverty and other problems, a huge increase in divorce, higher incidence of domestic violence, and women being 'used' and then discarded by men who will tell them anything just to acquire a warm place to put it for awhile.
I haven't looked them up lately, but I recall reading statistics that living together before marriage actually increases the probability of divorce after marriage, probably because the relation starts off with no clear commitment to each other. Also among both men and women, those who are promiscuous before marriage are less likely to be faithful after marriage and for most people, that one is a biggie when it comes to the qualities that make for good marriages.
And of course there are those who are just as convinced that the opposite of the statistics is the real truth.
I counsel young people to at least commit to a ring and a date before having sex. And the vast majority of those who do that go on to get married and from all indications are enjoying happy marriages that will last.
From my several generations down perspective, a lot of people chose to live together because divorce caused so many scars. I don't know the 'why' of that, because divorce is no different than ending a long-term relationship that has run its course.
When people don't have a spiritual background, then they live their lives as they see fit. When somebody
does come from a spiritual background, and
still chooses to cohabit - I find that odd. Just as I find it odd when those who have a spiritual background become sexually active.
Which is why I also find it odd that gays are denied the right to marriage. If sex is only acceptable when you are married, and they cannot marry - that seems a bit cruel.
Of course, in their shoes, I would just take my vows before God, without church or state officiating.