One in three adults admitted to "financial infidelity" in a recent National Endowment for Financial Education poll, and 76 percent of those respondents said the deception affected their relationship.
("It meant nothing!" may be harder to get away with when "it" affects your credit score.)
The national survey of 2,035 respondents age 18 and older found that three in 10 have hidden a purchase, bank account, statement, bill or cash from their partner. Sixteen percent said they've lied to their partner about how much debt they have, and 14 percent admitted lying about their income.
One of the most fascinating revelations is why couples say they aren't more forthright about their finances.
Just 16 percent said they lied because they were "embarrassed or fearful about my finances and didn't want my partner to know." Another 15 percent said they had never discussed finances with their partner and "feared they would disapprove" of the true picture.
A full 35 percent of respondents replied, "I believe that some aspects of my finances should remain private, even from my partner."
The deceived partners don't appear to agree, with 47 percent of respondents reporting that the deception eventually led to an argument and 33 percent reporting it led to "less trust in the relationship." Thirteen percent said it "ultimately resulted in divorce."
"Secrets cause fractures, and fractures cause divisions," says relationship and conflict resolution expert Melanie Ross Mills. "When we're hiding anything from someone we are supposed to be partnering with — in business, in marriage or in friendship — it's going to cause a division."
Financial experts at the National Endowment for Financial Education recommend couples take a "life values" quiz to help them start talking more honestly about money. (Questions touch on your thought process when purchasing a new car, how you define your ideal home and neighborhood, how you handle overdue bills, etc.)
Mills recommends scheduling regular "couples compass" meetings.
"Go through all the major areas — parenting, finances, intimacy — and have an honest discussion about where you're on the same page and where you're not," she says. "If you're not bringing each other in on your long-term plans, you're most likely not fully investing in the partnership."