Living with your bestie can be a bit of a learning curve. Sure, you’ve figured out how to decorate with a roommate whose tastes are a little edgier than yours. You’ve compiled a list of healthy snacks to fit her 2018 meal plan, because hey, you’re supportive like that. And since you compromised on celebrating Martini Monday (her fave) and Wine Wednesday (yours), you’ve packed all your best beauty products for a hangover. There’s only one thing left to figure out: Now that your worldly possessions are effectively doubling, what are you going to try on first? While it’s tempting to want to share everything with your bestie, according to the experts, there are a few items you should keep to yourself in order to avoid nasty health consequences.

1. Popcorn: Approach that family-sized bowl of snacks with caution. “Sharing finger foods like popcorn from a communal bowl is safe as long as everyone washes their hands beforehand to prevent fecal contamination and GI viruses like rotavirus or hepatitis type A from spreading,” says physician and medical researcher Dr. Briant Burke (developer of the HeelAid brush-on treatment for plantar fasciitis). Dr. Burke notes that even when you wash your hands, there’s still a risk of spreading colds and other respiratory viruses — but there’s no point in worrying about it. “That’s just part of being out of your house during winter,” he says.

2. Towels: One of the easiest bathroom DIYs on a budget? Upgrading your towel situation. But you do need to change them regularly, especially if they’re in a high-traffic area. “If you are using towels in the bathroom, be sure to wash [them],” says Dr. Alison Mitzner, a board-certified pediatrician. “Use only the one for you, and [do] not share any of them.” Dr. Mitzner also recommends switching to paper towels if someone in the family is feeling under the weather. “The best way to prevent infection is hand washing and covering your mouth while coughing and sneezing,” she says.

3. Lipstick: Your bestie tracked down the ultimate lipstick for dry, chapped lips, and now you’re ready to paint the town like RiRi. There’s just one problem: “Germs spread easily,” says beauty chemist David Pollock, who has developed products for Lancôme, L’Oreal, Smashbox, and Bliss, in an interview with Brit + Co. “If you have a favorite shade or want to help out a friend who insists on trying your newest find, use a tissue and wipe it off first in an attempt to remove the used layer and reveal fresh, new product.” Or, if you’re not comfortable wiping away precious lipstick, twist the tube all the way up and load a lip brush with color from the base.

4. A Glass of Wine: Urban legend has it that booze is safe to share, since alcohol kills germs. True or false? Both, as it turns out. While the alcohol content in wine is relatively low, and therefore unlikely to slay a virus, you won’t necessarily pass something along if you share a glass. “The risk of disease transmission from sharing personal items varies, depending on the item and the disease,” says HeelAid developer and physician Dr. Briant Burke. Still, if you’d rather be on the safe side, get your own glass. “It seems obvious to not share food and drinks,” says Mitzner, “although often it is hard to remember this when you are in a social setting.”

5. Mascara: We’ve all heard that sharing eye makeup is a no-no, but let’s face it: Even our drugstore faves don’t come cheap. Still, if your roommate offers up her collection to help with your hunt for the best mascara, resist the urge to test-drive. “Mascara tubes provide the perfect environment for bacteria and fungus to form, infecting and re-infecting your eyes with each use,” says Pollock. He warns that conjunctivitis, or pinkeye — a highly contagious viral infection — can go unnoticed in one person and cause huge problems for another. “This makes sharing eye makeup a big concern,” he warns.

6. Nail Clippers: “More than 60 percent of the world’s population has some form of nail infection caused by mold, yeast, or fungus,” says Dr. Mark Hinkes, a board-certified podiatrist. These infections can cause the nails to be affected by bacteria. “So, the likelihood of transferring the infection via use of an unsterilized instrument is fairly high.” Dr. Hinkes says that even wiping down your nail clippers with a topical disinfectant doesn’t guarantee cleanliness — that’s why an autoclave is a pedicure essential among trusted nail-industry pros.

What items do you hate to share? Tell us about it @BritandCo!

(Photo via Getty)