China's sexual revolution is underway, but it's a complicated, and sometimes contradictory affair. A new book by American journalist Richard Burger — of the popular Peking Duck blog — seeks to address those changes by studying China's sexual history over the past 5,000 years.

Behind the Red Door: Sex in China will be released tomorrow, and the introduction is certainly an eye opener:

Every year, thousands of Chinese women pay for an operation to restore their hymens shortly before their wedding so that husbands can see blood on the sheets on their honeymoon night. Brides-to-be who cannot afford the 4,400 yuan operation (about $700) can walk into one of China’s 200,000 sex shops or go online to buy a cheap artificial hymen that seeps artificial blood when punctured.