I don't see anything bad about an innocent kiss on the lips even in public.
But yeah, it shouldn't go to the extreme of French kissing. French kiss is bit too 'intense' for the public I reckon.
But I'm completely OK with a normal lip kiss in public.
In fact, as kosandpol said, we are doing what European invaders "ordered" us to do by not kissing in public. So we are still a set of puppets of European invaders.
About the culture... Culture is what people creates. If an act was there for a long time, it ultimately becomes the culture. We as Sri Lankans don't have a culture of our own. We are doing what Europeans have ordered or forced our ancestors to do. The best example is Kokis. Kokis is a Deutch food as far as I can remember. And there are many simple words in our sinhala vocabulary taken from those invaders.
On the other hand, if people are allowed to kiss in public, it will solve some of those problems like illegal rooms, abortions etc. Why? Because youth needs sex to a certain extent. At least a kiss they want.
What's happening now? Because they can't show their love by a kiss, or because they can't explore their sexuality, they tend to go to hidden places. Mainly cheap rooms. And they go to the extreme because it's hidden and they lose their virginity gets pregnent and then illegal abortion. All these would have prevented upto a certain extent if they can at least kiss their lover in public.
There is a kiss-phorbia created by the media people and so called cultural people who doesn't know our real culture. That's the main reason.
And it is scientifically proven if a person kisses his or her partner before leaving for work, he or she is more productive in the day. But what happens now... Father can't kiss the mother in front of the children. And the children doesn't see the love between their mother and the father... All those things affect psychologically.
Kiss on lips is not a bad thing. And it will not destroy our culture.
Only the people who doesn't know what actually a kiss means are the people who shout that it's bad because they don't know. And they have never kissed a person in an innocent way
