I don't think people realize how important the "mwaaah" part of kissing is. (That's the best term I can use to describe it. It's the action that ends the kiss, the sound that's made when the lips come apart from each other, making that smacking sound.)
But think about it, without that "mwaah", all you have is two people touching lip-to-lip (or lip-to-cheek), and then pulling away. Kissing would be so unbelievably awkward without the "mwaah".
Don't believe me? Next time you kiss your significant other, leave out the "mwaah" part. It's weird. It's borderline creepy. It's like two birds pecking at each other.
And all of this brings up a good point...Why do we do the "mwaah"? It's not something that's inextricable from the kiss, as the above little experiment just showed. It's not as if it's physically impossible to leave out the "mwaah". Yet we do it as second nature. Obviously, you can argue that the "mwaah" is what makes a kiss a kiss, and without it, it's simply not a kiss. But I'm not arguing about what constitutes a kiss, simply about how the kiss came to be defined as such. (No need to rehash the "No True Scotsman" fallacy, killer.)
Our ancestors must've realized how awkward it was to not have the "mwaah", and forced themselves to do it, day after day. Then, through many generations, we just became wired to give the "mwaaah" at the end of a kiss. And it really was a brilliant discovery by our ancestors. Not only does it alleviate any awkwardness, it gives the kiss a definitive ending point.
So really, we have to thank cavemen for:
1. Fire
2. The wheel
3. the "mwaah"
And I'll bet that's why cavemen clubbed women over the head and brought them back to the cave. It was just too awkward and embarassing to kiss them in public.
