A growing number of people are hiding bank accounts, credit cards and/or debt from their partners -- a phenomenon called financial infidelity -- according to a recent survey by CreditCards.com.
"About 40% of people in serious relationships are keeping a money secret from their partner," CreditCards.com's Ted Rossman said.
Rossman said the secrets can range from having a secret bank account to hiding credit card debt. He thinks one reason is the way relationships have changed from generation to generation.
"Millennials tend to get married later," Rossman said. "They've had more time to get entrenched into their own money habits. It becomes tougher to mesh that with somebody else."
In the survey, 51% of Millennials admitted to keeping financial secrets from their partner. That's higher than Gen X'ers, at 41%, and Baby Boomers, even lower at 33%.
Rossman thinks another reason could be that millennials were more likely to grow up as children of divorce.
"They remember when Mom and Dad split up," Rossman said. "Therefore, they keep a 'freedom fund,' if you will, in their own relationship just in case it doesn't work out."
The survey also showed that nearly 30% of respondents said hiding debt or lying about finances was worse than physically cheating, which 40% of people said was worse.
"The fix here is communicating early and often about our money," Rossman said. "I think most people ultimately are forgiving, but you don't want to let that secret fester for too long. I think the longer it goes on, the bigger the problem."
Rossman said that more couples are starting use three bank accounts: "yours, mine and ours." He said it's also important to talk about finances when in a serious relationship; even exchanging credit scores is good.
"The one thing you have to do before entering into one of these arrangements is agree on the parameters," Rossman said. "I know that it's not easy to talk about money, but I really do think that the secret ends up being even worse than the act itself."