(CNN) -- 'Tis the season for overspending -- just ask the 141 million people who raided retail stores online and in-person the weekend after Thanksgiving.
But before you buy that Red Ryder BB gun or Jelly of the Month Club membership, remember that relationship experts agree it's best to set economic expectations with your partner unless you want to end up on the naughty list next year.
"Financial infidelity," when a spouse or partner is not forthcoming about monetary decisions, can be insidious.
"All of us have some area of our lives where our impulses overwhelm our judgment, and spending -- especially at holiday time -- is a common one," says Joseph Grenny, co-author of the New York Times best-seller "Crucial Conversations."
"Couples feel shame and resentment about discussing spending mistakes, which drives them to silence."
According to a recent report from McGraw-Hill Federal Credit Union, 48% of heterosexual married couples have disagreements over how much to spend during the holiday season. And research by the National Council on Family Relations finds that financial disagreements are the type of argument that most strongly predicts divorce.
Just as sexual infidelity can start with an innocent kiss under the mistletoe at the holiday party, financial infidelity can also begin humbly -- whether it's lying about how much a new pair of boots cost or secretly cashing a check.
According to relationship experts, as with any other marital issue, financial fights have a larger underlying factor: a lack of trust.
"Financial infidelity is very apt because, like an emotional infidelity or an actual sexual infidelity, it's first of all doing something that at some level the partner would not approve of," marriage counselor Susan Heitler says.
Heitler, the author of "The Power of Two: Secrets of a Strong and Loving Marriage," says couples should agree on a dollar amount that each person can spend independently on holiday purchases -- this number will fluctuate depending on the household's financial situation.
Heitler says a particularly popular form of money management these days is for couples to maintain both individual accounts and a joint account, especially since two-working-parent families are now the majority in the United States.
If partners maintain separate accounts, Heitler says, there should be a discussion about the point when an individual's decisions affect the group. The key is to find balance between autonomy and partnership; nobody wants to ask permission for every single cup of coffee.
"As adults, you don't want to be asking permission, you want to be advocating your financial needs and working them out as partners," says marriage and family therapist Jane Greer. Greer's latest book, "What About Me? Stop Selfishness From Ruining Your Relationship," focuses on that battle of "I want" versus "you want."
Greer says financial infidelity usually occurs when one partner feels their pleasures are being denied. The experts see an obvious solution: Open up a conversation before opening up your wallet. But given the spirit of the season, some see the holidays as an opportunity to splurge a little -- especially on their partner or children.
For the little ones, iPads are among the top 10 most popular gifts for both girls and boys, according to a Prosper Insights & Analytics survey for the National Retail Federation.
"Tablets and smartphones continue to steal more attention from today's kids, leaving mom and dad with no option but to look for ways to get their children their own items -- and leave theirs alone," says Prosper's Consumer Insights Director Pam Goodfellow in a release for the survey.
Even though they're sure to bring huge Christmas Day smiles, experts say big-ticket items like electronic goodies shouldn't trump the budget.
"Surprises are nice, but shocks aren't. Few life partners are willing to trade a moment of glee for a year of interest. You can leave room for pleasant surprises by setting budget ranges," Grenny says.
If you absolutely are sold on an item and willing to make an individual (key word!) sacrifice to get it, it is your prerogative, Greer says. But you're potentially setting yourself up for an argument, too. An easy way to defuse the situation is to say, "You may be concerned, but it was really important for me to get this for you."
However, setting -- and abiding by -- a price range for splurges can help partners feel equally empowered.
The problem lies when money is taken from necessary appropriations, like food and shelter, Greer says.
Here's a simplified list of ways to discuss holiday finances with your significant other by Joseph Grenny, the author of "Crucial Conversations":
Talk early. Find a time to talk early about how you'll deal with this year's holiday spending. Don't wait until your spouse springs for a Harley to talk about limits.
Solve the right problem. Many couples don't reach a resolution because they discuss the wrong problem. For example, if you discover your loved one has rented storage units and stuffed them with hidden binge gifts, the issue now is trust, not spending.
Communicate with love and respect. The most important key to solving problems with loved ones is to ensure they know that you respect and love them. When they know you support and respect them, their defenses drop and they begin to listen.
Be willing to be wrong. Approach the conversation with an open mind. For example, it could be that the source of your conflict is not a real budget limitation, but that you don't value holiday gift giving to the same degree as your partner.
Hold each other accountable. Once you reach an agreement, find a way to routinely keep track of spending.