“For years, most Indian men used sex with their partners as a kind of sleeping pill, and few devoted any time to foreplay,” Dr. Kothari said. “Now, many women are able to ask for what they want.”

Aseem Chhabra, a columnist for The Mumbai Mirror, an English daily featuring local news, said public displays of affection are still a rare sight in India. “It’s not like you can walk on the streets of Delhi and Bombay and see people kissing. It’s still a big taboo,” he said.

“The educated 20-somethings are watching a lot more Hollywood films,” he said. “It’s not like they are imitating, but they are getting inspired.”

Six years ago, Richard Gere caused a national scandal when he kissed the Bollywood actress Shilpa Shetty during an AIDS-awareness event. Mr. Gere quickly fled India, leaving legal complaints and at least one arrest warrant in his wake. Ms. Shetty was criticized for failing to resist him.

A 2006 government-financed survey, the most recent available, found that less than 1 percent of female respondents and 5 percent of male ones said that they had had sex outside of marriage in the previous year. Other studies suggest that premarital sex rates are higher than reported in official surveys, but the numbers are still very low compared with those in the West.

Rajat and Neha, two 22-year-olds in New Delhi’s majestic Lodi Gardens, agreed to discuss why they enjoy kissing when their parents had not done so, at least in front of them.

“Love,” Rajat said simply as Neha nodded. Their parents’ marriages were arranged; they hope to marry for love. They asked that their last names be withheld, however, in part because they are from different castes and fear that her parents would not approve.