Editor’s note: Mary Claire Allvine is a personal finance expert and partner at Brownson, Rehmus & Foxworth—a financial planning firm in Atlanta, Georgia. She is also the author of “The Family CFO: A Business Plan for Love and Money” (later renamed “The 7 Most Important Money Decisions You’ll Ever Make”).

Fighting over money has long been part of the stereotypical loveless stuck-together marriage. Not enough money to live without strife; not enough cash to divorce.

As with most stereotypes, the truth is a lot more complicated and instructive. A few facts:

• Money arguments aren’t always caused by lack of income. Big earners can engage in big fights, just like those barely making ends meet.
• Financial disputes are an excuse for divorce, not the cause.
• Spenders do marry savers, pretty frequently. Some of them live happily!

If money isn’t the root of marital problems and income isn’t the solution, how do those savers and spenders ever stay together?

The most effective solution to these age-old problems is to separate the money from the problem. In finance, we advise car buyers to negotiate the price separately from the financing. In a marriage, successful couples (those who stay together happily and who, somehow, get to those life goals: Buying homes, getting out of debt, supporting kids, changing jobs, retiring) fight about the price and the terms separately.

When writing my book, “The Family CFO,” I interviewed dozens of couples and became known for my interest in how couples work out financial issues. At a party around that time, a woman sought me out, saying, “You work with couples on finances. You have to tell my husband to pay for the kids to go to private school!”

I probed a bit and found out that the woman had been a teacher herself before staying home with the kids. Her two boys were getting ready for middle school, and she had identified the environment she thought best for their learning styles.

So I sidled up to the husband later in the evening. “Your wife tells me you might be looking at a private school in your area,” I ventured. “She doesn’t understand a thing!” he bellowed at me. “We moved where we moved for the public schools. Now, if we’re going to get that lake house before the kids go to college, we need to be saving every dime!”

Aha! The husband had a whole trade-off in his head he hadn’t communicated to his wife. She was arguing about his control over money; he thought she wasn’t taking responsibility for the cost of a second home.

Now, most of us would love to have a fight about a private school vs. a lake house, but it wasn’t any more fun for this couple than for those of us who scream “I took a bag lunch all month, and you blow all the savings in one night!” What we screamers mean to say is “The money you spent on beers and golf could have reduced our credit card debt repayment by a full month.”

The secret to a constructive, not destructive, fight then is a three-step process:

1. Get your priorities in order before the fight breaks out. If your debt is stressing you out, tell your spouse. Lay out the trade-offs you recommend making to get the debt down.
2. Fight about the right thing: Getting out of debt vs. hanging out with the guys. It isn’t about the saver martyring her/himself over peanut butter bag lunches.
3. Write it down. Set a joint goal, then measure yourselves over time. It’s amazing the romance you can put in finance when you do it together.