A kiss is not a kiss. In some cultures it’s just gross, researchers find.

The Washington Post reports:

Researchers have discovered kissing helps you choose the right mate and helps you live longer. They have found you use 146 muscles when you pucker up and swap 80 million new bacteria when you lock lips. And you will spend some 20,000 minutes — or two weeks — of your lifetime doing it.

But the cultural significance of a kiss may not be that widely shared, according to new research published in American Anthropologist.

Researchers at the University of Nevada and Indiana University found fewer than half of the world’s cultures kiss in a romantic way. Although many societies consider kissing to be a romantic or erotic activity, others have gone as far as to call it “gross” and ask why anyone would “share their dinner.”

The researchers studied 168 cultures over the past year and found evidence of romantic kissing in 77 societies, or 46 percent, but none in 91 others.

No word yet on whether the progressives will redefine kissing as rape on American college campuses.