Little wonder, then, a visit to Shanghai’s Sex Culture Museum with its exhibits of 1,000-year-old dildos and Ming dynasty pornographic porcelain stunned him.

"It’s the first time I’ve seen anything like this," said 30-something Li. "This should be taught at secondary school. Not even my parents taught me about sex."

In pre-communist China, sex was less a taboo than it became under former leader Mao Zedong, whose own highly active — and disease-ridden — love life was chronicled by his doctor in a book banned in China.

Under Mao, sex was officially a matter of doing one’s reproductive duty for the state. He wanted a new labor force to build a new country and the state encouraged high birth rates.

Since then, the government has embarked upon a stern family planning policy to control a booming population — the world’s largest — but official attitudes toward sex remain puritan, though they are changing slowly.

They need to change faster, health experts say.

There has been a huge rise in pre-marital and teenage sex. According to state media, 70 percent of urban youth admitted to having premarital sex in 2004, up from just 15 percent in 1989.

HIV/AIDS in China is now increasingly spreading via sexual transmission, which risks exacerbating a problem that already afflicts an estimated 650,000 Chinese.

Reuters.com