I am about to say something that many might consider blasphemous -- I don't think couples should live together.

Now, before you cast me as some pro-marriage, uber-conservative who has been reading one too many National Marriage Project (NMP) studies, be assured I am not. At the risk of sounding somewhat Orwellian, let me clarify: Living together is OK for some couples and not for others.

Don't want to be parents? If there are no kids to deal with, planned or still at home, please -- move in and out with whomever you want as often as you want.

It's also OK for same-sex couples; until other states wise up and follow the lead of Vermont and Massachusetts and allow same-sex marriages, we haven't given gays and lesbians much of a choice, have we?

It works for people like me, too. As a divorced middle-aged woman who is about to be an empty-nester, shacking up -- with someone respected and accepted as part of the family -- works.

Finally, cohabiting is fine if you've put a ring on it -- an engagement ring, that is -- or have a wedding date in mind or have been talking marriage (to each other, obviously). Or, if you don't "need a piece of paper to prove your love," you at least know that you're committed to each other.

But if you are a young adult who thinks you might want to have kids one day and maybe even get married but you aren't sure that your current sweetie's The One, please don't move in with him or her.

I can hear the grumbling; "How will I know if we're compatible or not if we don't live together?" Easy -- you know because you've spent enough time together as a couple. If you really don't know if you can live with his smelly socks in the hallway or her panties hanging in the bathroom, then you either haven't known each other long enough or you haven't been paying attention. In either case, you're just not ready to marry. Please, date some more.

Couples rarely split up over socks and underwear; they split because of affairs, alcohol, addictions and abuse. They split because their expectations of marriage differ. And they split because they never should have been together in the first place -- probably because they moved in together to see if they could live with the socks and panties while they were ignoring other, much bigger issues.

So what's so wrong with living with your boyfriend or girlfriend? Let's forget the studies pointing out the booze (cohabitors drink more), weight (they're heavier) and happiness (they're not quite as happy as married couples but they aren't more miserable, either), because those aren't the issues. Nor are the results of the latest NMP study, "Why Marriage Matters," which predicts doom and gloom for the children of cohabiting couples. The NMP has an agenda; it wants to promote marriage. Still, even a recent and presumably agenda-less Pew Study finds similar results, at least when it comes to cohabiting couples' economic well-being; they're poorer, and that puts stress on a relationship. A lot of stress.

As a society, we need to pay attention because there are 12 times as many cohabiting couples today as there were in the 1970s.