In a perfect world, 24/7 honesty and openness in relationships would be a reality. But we’re not perfect and neither is the world — and there’s nothing wrong with keeping a few secrets from your significant other. (Some have even argued it’s a necessity in good relationships.) Let’s be clear: We’re not saying it’s ever OK to outright lie, and little white lies aren’t even something you should be doing on a daily basis. But keeping part of your life and thoughts private is healthy and important.

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For instance, does your SO really need to know that you think his or her mom is an annoying chatterbox after one glass of wine? Or find out that in your senior year of college you slept with 75 percent of your total number? Definitely not. Here are nine subjects that experts confirm are totally fine to keep to yourself when you’re in a relationship.

Crushes

Your partner doesn’t need to know about the eye candy in your daily life, whether it’s the sexy guy in the Armani suit you always notice on the F train or the cute woman with the music note tattoo who’s always in your favorite coffee shop. “Telling your partner about people you have casual, essentially meaningless crushes on won’t make them feel any better about themselves and could actually sow some serious seeds of discontent,” says Rita Delgado, a sex educator and owner of Shades of Love, an adult toy store in San Antonio, Texas. As long as things aren’t going any further than you thinking he or she is good-looking, then it’s no harm, no foul.

Beauty secrets

If you feel comfortable getting into the nitty-gritty details of your grooming routine, go ahead, but if it’s something you’d rather not reveal everything about, you’re not alone — and it’s completely OK. “Your partner doesn’t need to know about the Botox, laser hair removal or other body treatments you use to stay looking and feeling good,” says adult advice columnist Sarah Merrill, founder of BigKidProblems. The exception: Major surgery, like liposuction, in which case it’s a health issue and you should share the decision with your SO.

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“You-time” details

There’s no need for your lover to know when, where and how you pleasure yourself. “If you’re articulating when and where you’re masturbating, it could be seen by your partner as a sign that you’re not sexually satisfied, as well,” says Delgado. Leave this to his or her imagination, which can also be hot.

Weight gain (yours or theirs)

You and your partner don’t need to have conversations every time the scale goes up a pound or 5 — especially if you’re just not thrilled with the fact that he or she has put on a few. “Keep the fact that their overeating bothers you to yourself,” says psychotherapist and author Dr. Mike Dow. “Before you go into intervention mode or what could be perceived as criticism, start by modeling the behavior you want to see. People are more likely to be fit if the people around them are healthy and fit, so suggest going on a run or heading to a yoga class together.” Of course, every rule on this list has exceptions, and if weight is becoming a health issue, then it might be time to express loving concern. But generally, it’s your and your partner’s individual business what the scale reads on a day-to-day basis.

Sworn secrets

That thing some people say about how telling your partner secrets about other people “doesn’t count”? That’s totally false. “If you swore to one of your girlfriends that you’d never divulge the details of her sex life or work drama, then it should never be revealed to anyone — including your partner,” says attorney Corri Fetman. It doesn’t matter how close you are or how much you trust your SO. You’ve been sworn to secrecy, which is non-negotiable. Don’t sacrifice the integrity of one relationship for another. The exception: If one of your kids comes to you with a secret that concerns you, of course you can share it (in confidence) with your partner if he or she is co-parenting with you — just be careful not to get a rep with your kids about not being able to keep your mouth shut!

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Girls’ night out details

The major caveat for this rule: You don’t have to tell your SO the play-by-play of your friend’s bachelorette weekend or girls’ night out as long as you used good judgment. That means that if you’re in a monogamous relationship, there was no cheating or borderline questionable behavior — like serious drug use, for instance. “You can keep the details of that wild weekend on the strip to your best friends and yourself,” says relationship expert, Michelle Crosby. What happens in Vegas stays in Vegas, so to speak, and your partner doesn’t need to know how many singles you shoved into the G-strings of those Chippendales dancers. Hopefully, though, you’re close enough with your partner that you’d want to share some of the funny moments from these types of nights — but as long as you behaved, you’re under no obligation.

Your number

Yes, it’s actually OK to keep your number of sex partners private. The experts all agree that your number of lovers is no one’s business but your own. “It’s possible you had a wild period, which your partner might not love hearing about,” says dating guru Cathryn Mora, creator of the relationship-strengthening course LoveSparkMe. “Instead of delving into every detail, you can say things like ‘I was no angel,’ but there’s no need to divulge specifics, and I’ve rarely heard of that conversation ending well.” Ultimately, if you’re happy in your current relationship, what does it really matter anyway, assuming you’re both sexually healthy and safe?

Cyberstalking

“Oh, she went to Harvard? I had no idea.” It’s totally fine for that to be your response when your SO brings up his or her ex — even if you looked through three years of her Facebook photos and saw every haircut and job change she’s had. Experts say it’s fine to keep your investigative work a secret from your partner. Telling him or her may make you look suspicious or just plain jealous. “I’m not even friends with my boyfriend on Facebook and was able to find out a lot about his ex just by knowing her first name!” admits 31-year-old Stephanie, a teacher in Staten Island. “I would never tell him because I don’t want him thinking I’m jealous or worried — I was just curious.” Curiosity is fine — just don’t get too obsessive since that’s obviously not healthy, either.

Family feelings

Never reveal negative feelings about your SO’s family. They may seem to be OK with it at the time that you say it, but may resent you for it later — and that can get ugly since you can’t take it back. (Hint: He or she can bitch about their parents’ terrible taste in decor and cooking skills — but you cannot.) And if it’s your parents who aren’t fond of your partner, just imagine how he or she would feel knowing that — or how you’d feel if the roles were reversed. “Your SO might not want to spend the rest of their life knowing that members in your family don’t like them,” says Delgado. “If they’re in blissful ignorance, keep it that way by not sharing that passive-aggressive comment your mom made.” In other words, unless you or your family has something nice to say, don’t say anything at all.