Actually, that's what cohabitation does. Women bear the brunt of the consequences of sexual liberation, abortion, and the decline of marriage. Anyone care to guess what percentage of single-parent families are in poverty?
Percentage of families below poverty level that are female-headed is over 80%, iirc.
My wife and I didn't do that and I can't understand people who say "we need to try out living with the person" -- what do they mean by "try"? Everyone has got their quirks and habits that the other dislikes.
if co-habitation is a 'trial period' then one can always find SOMETHING to dislike ("oooh, she eats her boiled eggs large side up, I'm leaving...."). Marriage on the other hand is permanent, 'til death do us part. We don't believe that there is an out, hence you work at it and I believe that marriage is something both partners (yes PARTNERS) need to work at, each day.