Being in a relationship often means revealing your darkest secrets -- including those that are financial in nature. Yet 27% of millennials admit to keeping money-related secrets from their partners, according to TD Bank's latest Love and Money Survey.

The most common secret millennials want buried? Not surprisingly, it's credit card debt. Other common ones include having hidden bank accounts, gambling hobbies, and unpaid student loans.

But here's the problem with keeping such secrets: They could spell trouble for your relationship. In fact, 31% of millennials say they'd consider breaking up with a partner if they discovered he or she had hidden debt or a terrible credit score.

Man and woman seated across from each other at a table.

IMAGE SOURCE: GETTY IMAGES.

If you're keeping your partner in the dark about important financial information, you should know that you're likely playing with fire. A better bet? Get those issues out in the open, and let your partner help you work through them.

The benefits of opening up

It's not easy to own up to your personal financial shortcomings, but if you don't clue your partner in, not only might you alienate that person, but you'll also eliminate the option for him or her to help you. Imagine you and your partner live together, but little does your partner know that you're carrying a credit card balance that only seems to grow by the day. Once you share that information, your partner might suggest that you get on a joint budget that allows you to see where your money goes monthly and that helps you cut your spending in the right places to free up cash to pay down that debt -- and perhaps meet other important objectives too, like building an emergency fund or saving for retirement.

Your partner may also be more inclined to influence you to save money once he or she is aware of your financial woes. For example, rather than suggest going out to dinner several nights a week, your partner might instead start encouraging you to cook at home as a couple. Or your partner might agree to take over certain joint bills (say, cable and streaming services) so that you can use your income to chip away at your outstanding debt.

A supportive partner can help you improve on other financial deficiencies, too. For example, if your credit is poor, they might agree to add you as an authorized user on their credit card. Then, when that card gets paid off on time, your score will slowly but surely improve, making it easier and more affordable for you to borrow money when you need to.

The takeaway? Hiding your financial problems from your partner isn't going to make your life better. If anything, it could put your relationship in jeopardy and prevent you from getting the help and support you need to dig out of the hole you're in. Rather than go that route, sit down with your partner and come clean. One tough but important conversation could set you on the road to a more financially secure path -- and a more emotionally secure connection to boot.