Dear Mrs. Riches:
I recently discovered that my fiancee has a less-than-stellar record of paying bills on time. In fact, her FICO score is in the toilet.

I'm concerned about this on many levels: (1) she didn't tell me about her bad credit herself, (2) she and I will be commingling money and I don't want my good credit harmed by association, and (3) I'm alarmed that she has it in her character to be so careless with money. Her explanation is that she was raised by parents who were both lousy with money and so she never learned; she assures me she will start now that we're going to be married. But to be honest, I feel turned off by this revelation and worried that it will be an ongoing issue in our marriage. Yea or nay, Mrs. Riches?

--Concerned Groom-to-Be

Dear Concerned Groom:
Oh, dear. (This is a very big "oh, dear," indeed.) I will tell you up front: The two of you need to wait to get married.

There is so much I don't know about your situation. I don't know whether your fiancee is going to grow up and get responsible when it comes to money. I have no idea whether your relationship, in all other respects, is above reproach. But here is what I do know: Both of you should be concerned about entering into a lifetime commitment in which trust is shaky and the potential for a financial mismatch is so huge.

It's not that happily married couples can't differ in their money-management styles; it's that jointly managing money is tough for even the best and most seasoned of couples.

It just isn't easy merging two histories, along with two sets of habits, attitudes, and priorities about money. No surprise, then, that the topic that causes more arguments for couples than any other is money (followed by sex, work, children, and housework).

Allow yourselves more time to communicate about how you'd handle financial concerns and to develop trust. She will need to demonstrate that she can handle her finances in a mature way, by carefully watching her spending, systematically reducing her debt, and working to repair her credit. You will need to get a bit less priggish about your FICO (a superiority complex can get in the way of mutual respect), develop strong but not condescending communication skills, and see whether time restores your faith in your fiancee.

Just remember: Waiting doesn't cost anything. And even if you have to lose a deposit or two for a hotel ballroom or caterer, the expense pales in comparison with the cost of the average divorce in the U.S. -- an estimated $20,000 and counting.

Thank you for writing. Yours is definitely a cautionary tale for all other couples-to-be out there. It makes the question "What's your FICO?" seem like a pretty darn good idea.

Want to navigate the tricky subject of FICO scores with your honey? Try:

Fool contributor Elizabeth Brokamp is a licensed professional counselor who regularly talks money with her honey, Robert Brokamp, editor of The Motley Fool's Rule Your Retirement newsletter. The Fool has a disclosure policy.