Unless you've got some Julia-Roberts-in-Pretty-Woman type of aversion to it, kissing is usually the first point of intimate contact with a new bloke. It's a huge moment: it can lead to sex, the big M. . . or, if you're unlucky, a communicable disease.

We could write a thesis on how kissing might have originated (actually, someone probably has). "It's still a bit of an unknown though - we don't know whether kissing is a learned behaviour or something that comes naturally," says sexual anthropologist Dr Bella Elwood-Clayton. One theory: in primitive times mothers masticated food and passed it to their baby via their mouths. Mmm. Anyone for chowder? "Some scientists link kissing to a form of animal-like grooming, or a way of tasting and smelling potential mates for biological compatibility and good immunity," adds Dr Elwood-Clayton.

The best bit? The simple act of swapping spit is good for combating stress. Researchers from the University of Zurich, Switzerland, recently observed 51 couples for a week and found those who had more physical contact had lower levels of the stress hormone, cortisol. It also bolsters your self-esteem, according to Dr Vivienne Cass, sexual therapist and author of The Elusive Orgasm. "Kissing can make you think, 'I am loved and desired; my partner enjoys me," she says.

Locking lips can also reveal a bit about a man's character. "If your partner doesn't tune into what you like, it might signal he's selfish, egotistical or ignorant," explains Dr Cass. "Conversely, if your partner is very 'polite': not kissing you unless you welcome it, is very tentative and lets you do all the leading, he may turn out to be passive and afraid to assert himself. That's not to say you can't verbalise what you want in a kiss." But if he pays no attention? Don't keep flogging a dead horse.

Lip schtick

We asked Tracey Cox, sexpert and author of the Kama Sutra for her top smooching tips.

Finger lickin' good: use your tongue to explore his hands - the skin between the fingers is particularly sensitive.

Lip service: Tantric sexperts believe there's a link between the clitoris and the upper lip. Get him to tongue your frenulum (the connective tissue between your lip and your gum) while sucking your top lip simultaneously.

Eye opener: close your eyes and have your partner kiss you erotically on the mouth while you masturbate to orgasm. As you're about to climax, open your eyes and look directly into his. Intense.