India's views on sexuality are actually very complicated. It's hard to generalize because India is such a huge and diverse country; few Indians even speak the same languages. However, if I had to generalize, I would say that the Kama Sutra is not considered erotic; it is considered a tool for Hindu women, who are born to bring their husbands to enlightenment in the hopes that they may earn enough good karma to be reincarnated as a man. In public, men and women are both supposed to be modest.
Muslim women do not even get a whiff of the Kama Sutra; usually, Muslim families expect the husband to teach the wife about sex after they're married, or the mother takes her daughter aside and gives her the rundown.
As to why there is no "public kissing," cause I get asked that a lot...well, in Bollywood movies, you rarely see people kiss on the mouth. Even in modern movies, they may kiss all over the neck and stomach and such, but they'll often avoid each other's mouths. Americans think, "Well, kissing on the neck is way more sexual! These people are weird!" But why? What makes it sexual to Americans? Ask yourself that before you judge, folks. Kissing on the mouth is considered sexual in India because you share bodily fluids. You're not supposed to eat off of somebody else's plate, either, because most Indian food is eaten with your hands, so you've been touching your spit, then touching your food.
I'm relatively sure it's legal to kiss your spouse on the mouth in public nowadays.
