Cohabiting before marriage may be the “kiss of death”—or divorce.

What are the odds that you’d be in this relationship if you weren’t living together? The more you get to know your possible future spouse before you live together, the better chance you have of breaking up with the wrong person and finding the right one.

Many times when you marry someone you’ve been living with, you marry someone you wouldn’t have otherwise married. Most women think that living with a guy is a step to marriage. Talk the guy into living with you, and you’re halfway to a ring. The problem is that after you’ve made a commitment to live together, if you realize that you’ve made a mistake, it is more difficult to disentangle yourself.

Couples who have a firm commitment to marry (already engaged or have set a wedding date) before moving in together have a better chance at a successful marriage.

People beginning a relationship should keep their own apartments, cars and cell-phone plans. Instead of jointly buying a dog, buy a fish. By prematurely constraining yourself you are closing out other options. The best chance for a happy, lifelong marriage is to keep your options open when you’re young.