Illnesses such as Mononucleosis, known as the 'kissing disease,' can leave you incapacitated for months." Surprisingly, though, the spread of bacteria during kissing isn't all bad.

Before you swear off kissing (and spoon-sharing) altogether, it’s important to note that the risk of getting a cavity is likely based on your response to the bacteria, Quartley says.

An intriguing, though entirely theoretical, suggestion made by Colin Hendrie and Gayle Brewer in 2010 is that kissing might be an evolutionary adaptation protecting against microbial disease.

States are warning beachgoers about a summertime surge in infections from a frightening, flesh-eating bacteria found in coastal waters.