01/07/2012 02:42 pm ET | Updated Mar 08, 2012

3 Times You Should Commit Financial Infidelity This Year

Chances are, you've heard about the other way to cheat on your spouse, the one that doesn't involve a trip to Vegas or a tryst with a co-worker. In fact, this kind of playing around never involves anybody else. It's all about you -- and your bank account.

These days, lying to your partner about how much you spend, save or borrow all fall under the same general heading of "financial infidelity." And according to the most recent data, quite a few of us are getting it on with our checkbooks.

Chances also are, you've come across an article or blog somewhere, or seen a credit counselor or marriage expert spouting the same mantra: tell the truth (the whole truth, and nothing but the truth) or risk ruining your relationship for the long haul. If not, google "financial infidelity" and you'll get a screen full of advice about how not to do it and why financial transparency is always the key to a stronger marital bond.

I have to disagree.

As an estate planning consultant and family finance writer, my job is to talk to lots of couples about their most intimate spending habits and their short and long-term goals for their family's future. And I've seen three types of relationships where a healthy dose of financial hanky-panky is actually the best thing for the marriage in the long run. So before you pledge your undying financial faithfulness to your partner, ask yourself whether you fall into one of these categories, and it pays to stray a little-- financially speaking-- in the New Year.

1. You've Got A Rock Solid Relationship

Except you just don't see eye-to-eye on some of the "finer things" in life. I've spoken to numerous couples who truly can communicate about everything. But when it comes to the price of certain discretionary items (say, how much a pair of shoes or golf clubs should cost to use a stereotype), they just can't seem to get on the same page. So here's what I say: why not agree to disagree and give each other the room to consume a few items here and there without any input as a couple?

A note of caution, though. Before you try this strategy, make sure you and your spouse satisfy two important criteria: 1) you've got a really strong bond (be honest with yourself, because if you have any other deeper, unresolved issues, this isn't the way to go) and 2) you're working towards the same broader goals: saving for college, retirement, buying a home, whatever you both envision for your family's financial future.

In fact, Sara Oliveri, a Family and Relationship Coach with a Masters in Applied Positive Psychology from The University of Pennsylvania, told me she encourages many of her clients to consider three bank accounts: one for their joint family expenditures, and one for each spouse so everyone has his or her own purchasing power. As Sara Oliveri explains: people should try to understand why some items are so important to their spouse's definition of happiness, without seeing it as a character flaw.

2. You've Got A Rocky Relationship
By the same token, it's certainly OK to bend the truth about your finances if you're going through a prolonged rough patch in your marriage. I see couples all the time that could benefit from a little forward financial thinking-- in case their best efforts to save their relationship don't pan out down the road.

I've also run into plenty of cases where a husband or wife doesn't think their spouse has the greatest head for financial matters. As a realist, I know that couples can have complicated relationships with money and with each other-- and still stay married for decades. Don't get locked into a "100% honesty is always the best policy" frame of mind. If your partner has a nasty credit card habit or invests in business deals that always seem to go south, it might make sense to stash some of your hard-earned cash in a secret account for a rainy day, especially if you have young children to worry about. There is one absolute in my book: a child's long-term security should always come before any issues you're trying to work out in your relationship. And if that means hiding money from your spouse, so be it.

3. You've Got Your Own Grown-Up Kids
The third case where I often encourage a husband or wife to keep financial secrets from a spouse is when one has grown kids from a previous relationship. By definition, blended families are tricky business, but I firmly believe that adult children from an earlier marriage have a right to a certain degree of financial autonomy from their mother or father's current partner.

For example, if an adult son or daughter asks you for money and requests that the conversation be kept private or just doesn't feel comfortable sharing some of the details with their stepparent, it's not "cheating" to respect your individual bond with your adult child-- as long as the amount you're gifting or loaning doesn't, in any way, jeopardize the long-term financial goals of your present marriage.

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