The overwhelming presence of men at the festival mirrored a demographic imbalance in China, where decades of the one-child rule and a cultural preference for sons combined with illegal sex-selective abortions have distorted the country’s gender ratio to 118 newborn boys for every 100 girls in 2012, rather than the normal 103 boys. In Guangdong Province, home to a migrant worker population of 30 million — China’s largest — the scarcity of women leaves bachelors with limited options.

Filling an exhibition center here in the capital of Guangdong in southern China, the festival was a three-day mating ritual between capitalism and hedonism, all diligently observed by that most prudish of chaperones: the Chinese government. Erotic possibilities abounded, including a transgender fashion show, sliced deer antler marketed as an aphrodisiac, naughty nurse costumes and some flesh-color objects disconcertingly called “Captain Stabbing.”

Three decades after China began shedding its priggish Mao-era mores, sex is now a big business here. Across the country, pink-lit “hair salons” staffed by provocatively garbed women compete with massage parlors and late-night paid companions who slip their business cards under hotel room doors. Those looking to enhance their encounters can shop at countless “adult health product” stores and on the Internet.