Traveling can be great for couples. Not only will you share some amazing experiences with your other half, but you’ll also get to know each other extremely intimately. Sometimes too much so. The secret to finding a balance and making it work? Drawing boundaries.

Of course, this is easier said than done: When suitcase space comes at a premium, it can be tempting to share rather than double up. And all that together time means you’ll end up experiencing things you’d perhaps prefer they kept to themselves — like snoring and bathroom habits. To help you draw the line, here are 10 things you should never share with your partner while traveling.

1. Toothbrushes

Losing your toothbrush and using your partner’s might seem like no big deal. After all, you share spit when you kiss, so how’s a toothbrush any different? Bad news — it is.

Your toothbrush harbors all kinds of unique bacteria. When it’s from your own mouth, it’s fine because your body’s used to it — but when you swirl someone else’s bristles around your teeth, you introduce new germs, which might not work well with your immune system. According to the American Dental Association, doing this leaves you vulnerable to all kinds of viral infections, including colds and cold sores. Team this with traveling exhaustion and an unfamiliar diet, and you’ve created the perfect storm for bugs and sickness.

2. Big secrets

When you spend loads of time with someone, you get to know them pretty intimately. It may be tempting to jump on this new feeling of openness by baring all. But here’s the thing: Don’t do it. Or at the very least, think about your motives. Is it because you think it’ll make them feel good — or because it’ll make you feel better at the expense of their own happiness?

If it’s the latter, reconsider. Learning about things like past infidelity, sexual baggage, or serious money problems can be extremely painful. Tearfully blurting it all out while you’re both in an unfamiliar place and living in close quarters with each other isn’t just irresponsible — it’s cruel because it’s harder for your other half to get some space. If you think the relationship can be salvaged and want to come clean about something, wait until you’re home and work through it together with the help of a therapist.

3. Earbuds

Ever asked to borrow earbuds off someone and looked down to see a blob of earwax looking back at you? If you answered yes, then you’ll know the dilemma that follows: return immediately and embarrass the owner or hold onto them for a bit (without inserting) before handing them back and risk them thinking you produced said blob. Long story short: Don’t borrow someone else’s earbuds. Aside from the awkwardness, it’s also unhygienic. Just like borrowing a toothbrush, sharing anything you put in an orifice without thoroughly disinfecting beforehand could result in an infection because you’re introducing unfamiliar bacteria into your body.

4. Solo masturbation habits

Regular masturbation is a normal part of enjoying a healthy sex life — and just because you’re traveling with someone, it doesn’t mean you should stop enjoying a bit of you time. Yet despite the physical and emotional benefits, many partners feel uncomfortable when confronted with their OH’s self-love schedule. It’s easy to see why: Knowing the person you love is finding gratification alone, rather than with you, could be upsetting. But in reality, rather than it being cause for concern, masturbation might actually be a sign that things are going well and be a complement to an already active sex life.

Whichever side you’re on, try not to stress out about it. Openness is an important part of having a healthy relationship, but that doesn’t mean you need to disclose everything. Some partners get off on the idea of their OH indulging, but if you think it’s more likely to bother them, you’re perfectly within your rights to masturbate and not tell them. It’s only ever a problem if one person is doing it to the point it’s detrimental to the relationship.

5. Prescription medicines

It can be tempting to share prescription meds while traveling to save on time and money and to relieve symptoms fast, but the consequences could be serious — even fatal. When you pop someone else’s pills, you’re not accounting for the meticulous consideration a trained medical professional has put into that prescription. You might not fully understand the drug’s use, side effects, and withdrawal symptoms. You might not know whether you have to take it with food, or avoid mixing with alcohol or other drugs. It might mask an underlying medical condition that you should get checked out. It could also be the wrong dose for your body size and weight. In short, taking someone else’s pills is a big health risk — something you probably don’t want to do while in an unfamiliar country.

6. Bathroom stuff

There are two types of couples: those who are unaware their sweetie has a digestive system and those who poop and fart in front of each other. There are pros and cons to both: According to marriage counselors, couples who fart together stay together because they’re more open and relaxed in each other’s company. Then there are other couples who think letting rip means the romance is dead.

Depending on your own stance, it’s considerate to err on the side of caution and keep toots and poops held in until you’re somewhere it won’t bother your partner. This is especially important when traveling. Speaking to HuffPost, Kurt Smith, a therapist who specializes in counseling men, said that passing gas in front of each other can also be a selfish or inconsiderate act. “If your partner is not making an effort to control it, move away from you, or say ‘excuse me,’ then it’s an example of disrespect that could be evident in other areas of the relationship.” So don’t stink up a tiny hotel room, and let your other half know if they should wait a minute or 10 before going into the bathroom after you.

7. Razors and nail clippers

Giving your legs a quick going-over with your partner’s razor isn’t just irritating because you’ve blunted the blades — you also risk catching something off each other. Razors can spread germs, fungal infections and most worryingly, blood-borne bacteria including Hepatitis B and C. The same goes for nail clippers, tweezers and any other objects that could come into contact with your partner’s skin or body fluids. If you absolutely must use their kit, then wipe it down with antibacterial wipes or douse it in boiling water before use.

8. Detailed information about your exes

This one applies to couples whether they’re traveling or not, but it’s especially important to abide by this rule while on the road. If you used to travel with your ex, now is not the time to compare every experience to that — especially if you’re visiting the same destination. When you bring up your ex, even if it’s negatively, you’re forcing your partner to think about them, which is never fun. The same goes for talking about past sexual experiences. If you had mind-blowing sex with an ex, you don’t need to tell the person you’re with right now. If there are things you’d like to recreate, or you’d like to spice up your sex life in general, then that’s definitely a conversation worth having. Just leave comparisons or criticisms out of it. And while it is important to detail any baggage (emotional or sexual) you may have, you don’t need to go into a play-by-play run through so they can picture every detail.

9. Devices and passwords

Every couple is different. Some are happy sharing passwords and devices — and if that’s you, then carry on. If you don’t, then traveling is no reason to start.

Everyone is entitled to their privacy, and just because your partner doesn’t want to give you their passwords or share their device with you, it doesn’t mean they’re cheating or up to something shady. They may just be a private person. Or perhaps they’ve been googling embarrassing medical things and don’t want you to see. Or maybe they write Dungeons & Dragons fanfiction and want to keep it quiet. Either way, it’s not up to you to decide if you get unfettered access just because you don’t feel like packing two laptops.

Another reason not to share devices while traveling is that things like battery life and accidental damage can cause arguments when you’re in a place where charging/repairs/replacement might not be easy. So where possible, keep to your own.

10. Insecurities and annoying habits

One of the great things about traveling with someone is you get to know them extremely well. This isn’t always plain sailing: Endearing quirks and bad habits rise to the surface alike. The difference between turning this into a positive experience rather than a negative one is how you deal with it.

If they’re being an inconsiderate jerk, then by all means, sit down and have a conversation with them. But for other things they can’t help — like a clicky jaw or a need to have lots of personal space, then you need to compromise, find a solution, or keep quiet. The same goes for bringing up things they might be insecure about — like their weight, snoring, or clumsiness. Be extra considerate when it comes to taking photos and comments you make about how the photos come out. When in doubt, be kind. And if you really just can’t deal with their habits or keep your thoughts to yourself, then hey — maybe it’s just not meant to be.