>>40
do you listen to green day?...

anyway, from howstuffworks.com:

Anyone who has ever been kissed knows that the sensations involved aren't confined to the mouth. Your facial nerve carries impulses between your brain and the muscles and skin in your face and tongue. While you kiss, it carries messages from your lips, tongue and face to your brain to tell it what's going on. Your brain responds by ordering your body to produce:

* Oxytocin, which helps people develop feelings of attachment, devotion and affection for one another
* Dopamine, which plays a role in the brain's processing of emotions, pleasure and pain
* Serotonin, which affects a person's mood and feelings
* Adrenaline, which increases heart rate and plays a role in your body's fight-or-flight response 

When you kiss, these hormones and neurotransmitters rush through your body. Along with natural endorphins, they produce the euphoria most people feel during a good kiss. In addition, your heart rate increases and your blood vessels dilate, so your whole body receives more oxygen than it does when you're just standing around. You can also smell the person you're kissing, and researchers have demonstrated a connection between smells and emotions.

also for >>27 from the same site:

Cooties from Kissing?
Most people know that mouths are germy places. Kissing is directly tied to a few illnesses:

* Mononucleosis is often called "the kissing disease" because it is carried in saliva and can be spread through kissing.
* The herpes simplex 1 virus causes cold sores and is easily transmitted through kissing.
* Although kissing doesn't necessarily cause meningitis, researchers have tracked a correlation between teenagers' number of kissing partners and likelihood of developing the disease.
* Some researchers theorize that bacteria that cause gastric ulcers may spread through kissing.
* It's unlikely that a person will contract the human immunodeficiency virus (HIV) through kissing, but the United States Centers for Disease Control has reported one case of HIV transmission contracted this way. 

But it is such an enjoyable exercise, why let something as simple as your fear of cooties get in the way of it?