Just as you can catch a cold from kissing a contagious person, you can also catch a cavity, reports The New York Times.
Cavities are caused by bacteria that stick to your teeth and feed on remnants of your last meal. These bacteria then release acids that eat away at your teeth.
Parents can pass these bacteria to their children—who are particularly vulnerable—when they taste their food to see if it is hot before spooning it into their mouths. And partners can pass it to each other by kissing, a number of studies have found.
One 40-year-old woman who had never had a cavity suddenly got two after she began dating a man who had periodontal disease and hadn’t been to a dentist in 18 years.
To protect yourself, make sure to floss and brush at least twice a day. And have your partner do the same!