This is not about culture rather about religion. I think that this rule is common to all 3 major religions without exceptions. It is sad and equally unfortunate to see that religions have been commercialized, I.e... Ramadan is more about food than cleansing ones self of sins by doing good, Christmas in the west particularly in the US has turned into a materialistic event that people look forward to each year with total disregard to the lessons and values we get from those yearly events. I think sexual behavior should be controlled and should be kept private. What happened to Prophet Muhammad's teachings and the ten commandments? come to think of it kissing in public is a violation in the christian faith even having a BF/GF is absolute adultery. The bottom line here is kissing in public and committing other sexual acts has only led to more problems in society morally speaking. just look at how many kids are born out of wedlock each year.... the number is astonishing and that's just partly a by- product of publicly displaying sexual behavior. Just my 2 cents.........