You don’t have to be 100 percent transparent to have a happy marriage.

By Marisa Cohen
Updated September 12, 2017

Deep down, you’ve probably got a few secrets you’ve never told anyone—including the person you’ve sworn to be true to for the rest of your life. But that’s okay! Everyone is entitled to keep a private little vault inside their brain where certain memories, fantasies, and feelings can live, without being shared with their partner, says Randi Gunther, PhD, a marriage counselor in Southern California and author of Heroic Love.

She cautions, however, that it’s crucial not to keep any secrets that could harm your relationship if they were to come out. “There is privacy and then there is secrecy,” she says. “You shouldn’t do anything away from your partner that he or she would be hurt by if were they to know.” Here are five things you can stay mum about:

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You Have an Innocent Little Crush.

Even if you’re in a monogamous relationship, you can still enjoy watching your ultra-fit neighbor jog by your house every morning or chatting about mid-20th century fiction with the handsome young clerk at the bookstore. “These secret desires happen for all people,” says Gunther. “They’re harmless—unless they begin to take over your thoughts or feelings and challenge your mutual faith in each other.” In other words, keeping that crush in your head (even fantasizing about the object of your desire) is perfectly fine, as long as you aren't tempted to act on it.

You Think His/Her Friend Is Really Annoying.

If your partner’s best friend is so offensive that you can never be around him without wanting to scream, well, that’s a problem the three of you have to work out. But that guy from high school he hangs out with a couple of times year who has the world’s most irritating laugh and smells like an old beer can? Keep it to yourself. Sharing your feelings about every one of his buddies will only cause friction—and you can bet he doesn’t love every single one of your friends, either.

Your Best Friend’s Secret.

Many people assume that when a close friend makes you pinky swear not to tell anyone her secret, your partner is the one exception to the rule. But you and your spouse are not a single entity, and unless she specifically says it’s okay to share information about her illness/affair/new job/whatever, be a good friend and keep it under lock and key.

That One Embarrassing Moment From Your Past.

We’ve all done something we wish we could erase from the history books, whether it was a major romantic fiasco, a short-lived stint in a job you failed miserably at, or even that time you sang lead in a truly terrible Go-Go’s cover band. “As long as there wasn’t any lasting trauma, you've worked through it, and there is no way your current partner will ever know about it, those memories are yours to share or not,” says Gunther.

You Sometimes Like to Sneak Off and Eat an Entire Box of Junior Mints at a Bad Movie.

Hey, we all have our little hideaways where we can be alone with our thoughts and our indulgences, not answering to anyone else. And the best thing about them is that they’re secret. As long as you’re not outright lying and hiding from your partner when she’s expecting you somewhere else, you can just tell her you need some me time—no details required.