And while kissing may feel oh-so-good, it also has health benefits, too. It triggers a whole spectrum of physiological processes that boost your immunity and generally spruce up that body you work so hard to keep attractive.

"Women say they can tell if a relationship is going to work after the first kiss, after the first night of kissing," he says. "They just get a feeling, an intuition."

" Kissing is passion and romance and what keeps people together," says Michael Cane, author of The Art of Kissing , who "lectures" on kissing at colleges around the country.

Kiss Me, You Fool

Among the benefits of a good wet one: That extra saliva washes bacteria off your teeth, which can help break down oral plaque, says Mathew Messina, DDS, a private practice dentist in Fairview Park, Ohio, and consumer advisor for the American Dental Association. "Still, I would not go around advocating kissing after meals instead of brushing," he says.

A serious, tongue-tangling French kiss exercises all the underlying muscles of the face -- which some say could keep you looking younger, and certainly looking happier.

Kissing might even help you lose weight, says Bryant Stamford, PhD, professor and director of the health promotion center at the University of Louisville. "During a really, really passionate kiss, you might burn two calories a minute -- double your metabolic rate," he says. (This compares to 11.2 calories per minute you burn jogging on a treadmill.)

When you give sugar, you actually burn sugar. Sex sparks a good calorie burn, Stamford says, especially "if you're passionately involved, thrashing around. If things were really hot and heavy, you might be looking at a caloric expenditure similar to a brisk walk."

But don't confuse great sex with a cardiovascular workout, he says.

"People tend to have the misconception that anything that raises your heart rate has the same effect as jogging, so it must be good for fitness. Not true," he says. "Anything can get your heart racing ... that's just adrenaline."