EVERYONE remembers their first kiss. The butterflies in the stomach before that moment when your lips meet and the chemistry explodes.

A long, passionate kiss with someone you fancy can send your heartbeat racing wildly and leave a smile on your face for days to come.

Dr Petra Boynton, sex psychologist, believes in the power of the kiss for maintaining mental health.

She explains: "A good kiss can increase self-esteem and the general feeling of well-being. It is very intimate, the closeness, and makes you feel good and of course it is also a trigger for sexual arousal.

"It's usually very erotic as there will have been a teasing build up before the moment of the kiss."

Being up front and personal with a new partner is a fast way to find out if there is any chemistry. The body releases pheromones which are attributed with sparking attractions based on subtle smells. People sub-consciously chose a smell which complements their own.

And for long-standing couples, a close encounter of the kissing kind can reinforce the relationship, according to Dr Boynton. She believes it is neglected as couples become familiar with each other. They tend to forget that kissing can be enough in itself as a perfect way to spend an evening.

"We rarely kiss without getting close to someone," she explains. "It's like an invasion of privacy with the other person's blessing. It reinforces your relationship because you are allowed into a space where not many people are allowed to go."

GP Alasdair Wright says the first kiss between a couple is the best. "There's nothing like the first kiss. It's the most intense kiss you can experience."

But whether it's the first time or the millionth -- everyone should be indulging in some tonsil tickling. It will not only prove to be a sensual delight but puckering up is actually good for you.

Dr Wright explains: "The lips are one of the most sensitive parts of the body and kissing gives enormous sensory stimulation. It sends signals to the brain to release endorphins -- the brain's equivalent of morphine."

The excitement of being close to someone you like stimulates the brain into further production of these happy chemicals' and the effect is euphoric.

"It is the same substance you would release if you were doing a bungee jump," he explains.