While you and your significant other can be perfect for each other in 101 ways, it’s still possible to be financially incompatible with your partner. Not everyone is a money whiz, and that’s OK. But ongoing problems can quickly put a strain on your relationship, and even lead to problems down the road. So how bad is too bad, and how many problems are too many problems? Luckily, there are ways to find this out, and you don’t need to hire a detective to do so.

According to Tina B. Tessina, PhD, (aka “Dr. Romance”), a psychotherapist and author of How to be Happy Partners: Working it out Together, it’s possible for couples to commit “financial infidelity.” This happens when “they haven’t established good communication, they’re trying to avoid conflict, or they’re out of control and don’t want to admit it,” she tells Bustle.

Ongoing financial problems can be a sign your partner isn’t prioritizing you, Tessina says, and that they lack self control. “It can be every bit as harmful as sexual infidelity,” she says, “even if most people don’t take it as seriously.” Here are relationship money red flags to watch out for, because the sooner you start to spot them, the better.

They’re Secretive About Where Their Money Goes

Maybe you find a receipt, or several, for a purchase your significant other made, and they get defensive when you bring it up. Normally, you wouldn’t care, but you’re both saving up for a big trip, and this purchase put a dent in the fund.

The problem here isn’t so much that your partner spent money without telling you; it’s that they snuck money out of a joint savings account and then lied about it, as neither bodes well for the future.

Out-of-control spending, lying, and hiding finances can destroy a relationship, Tessina says, so this is an issue you’ll want to work on, possibly by attending counseling together.

They Hide Their Debt From You

So many people have student loan debt, and that in and of itself is not a problem. It’s only a red flag if your partner lies about having debt or downplays how much they have, especially if you plan to get married, as it will then become your debt.

In that case, the debt, as well as the lying, becomes the issue, Tessina says, and it can even be a sign your partner is in denial. In this situation, she recommends seeking debt counseling and/or relationship counseling to begin fixing the debt — and to save your marriage.

They Have A Credit Card Problem

Another story: I know someone whose partner became addicted to credit cards, so much so that her compulsive shopping habit started to take precedence over their kids’ needs, like school supplies. He threatened to divorce her unless she cut up all her credit cards and got help from a financial advisor.

If you find yourself in a similar situation, know that it’s a slippery slope. Before things get even more out of control, you may want to ask your partner to seek money management help, Tessina says, or to see a therapist in order to get to the root cause of their overspending.

They Can’t Stick To A Budget

You may have been taught good money habits, but the same might not be true for your partner. So if they clearly aren’t able to stick to a budget, find a time to talk about money, and see if it’s something you can work on together.

It might be tricky at first, but “supporting each other while building a budget could help you reach your financial goals faster, and can even bring you closer together,” Brianna McGurran, a student loans and personal finance expert at NerdWallet, tells Bustle.

One way to begin is by creating a 50/30/20 budget. “It suggests spending no more than 50 percent of your after-tax income on necessities, no more than 30 percent on wants, and at least 20 percent on savings and debt repayment,” McGurran says. “If that sounds hard to achieve now, try making small changes at first, like negotiating down your cable bill.”

They Don’t Pay Their Bills On Time

While everyone makes mistakes, and encounters the occasional money issue, take note if your partner consistently pays their bills late — and even more so if they don’t seem to notice or care.

If you live together, this should be an even bigger red flag not only because it impacts you financially, but because it shows your partner isn’t considering you, or how their bad habits affect the relationship.

They Have No Savings Or Investments

When you mention “401(k)” to your significant other, do they panic? Or, worse yet, ask you what that means? If they have no savings at all, and don’t even mention investments, it’s a cause for concern.

Their inability, or lack of desire, to save money could affect you one day, McGurran says, especially if you plan to move in together, or buy a house. So talk to them about building better money habits, which might include putting portion of their paychecks into a savings account, or asking their employer about contributing to a 401(k).

They Have Bad Credit

Does your partner cringe or change the subject when you ask what their credit score is? Although bad credit in and of itself does not have to be a dealbreaker, if your partner has a lot of other financial red flags, you may want to take this one more seriously.

“[It] could affect you if one day you want to rent a place or buy a house together and your partner’s poor credit holds you back,” McGurran says. So you may want to suggest a plan to help them pay off debts, and begin building their credit score. Money problems are, after all, something you can tackle together.