7 Horrifying Things That Can Happen When You Kiss

For the same reasons you wouldn’t share a fork with a stranger or, say, lick an ATM, inserting your tongue into someone else’s mouth can set your body up for disaster. Here’s how:

1. IT CAN EXPOSE YOU TO NASTY BACTERIA THAT MAKE YOU FEEL MISERABLE.

“Mouths can serve as a transmission route for germs because there is close connection with the gastrointestinal and respiratory systems, and these are common sites of infections for germs,” explains Kelly Reynolds, PhD, a microbiologist at the University of Arizona’s Zuckerman College of Public Health. And that goes for people who seem perfectly healthy, since humans can shed pathogens through saliva for a few days before and after experiencing symptoms.

As you might imagine, open-mouthed kissing is particularly icky: It transfers more germs than closed-mouth kissing, and the more germs you’re exposed to, the more likely you are to get sick, according to Reynolds.

While not kissing anyone at all is the best protection, simply not kissing people who have a fever (a telltale sign they’re contagious), seem run down, or feel like they’re getting sick can also help. Otherwise, kissing could mean you get a strep or staph bacterial infection, or in some cases, a cold or the flu (although you’re actually more likely to contract those from inhaling the particles an infected person expels when they cough, since germs suspended in the air are more likely to be inhaled deep into the respiratory passage, according to Reynolds).