Xiao Shuang's son blames his mother for the break-up of his family, but she cannot bring herself to tell him the truth.

When Xiao Shuang, 58, discovered her husband was gay more than 10 years ago, divorce became inevitable. "My husband never comforted me when I was in pain, never talked sweetly to me, never kissed me in more than 20 years. But still I can't tell my son that his father is gay."

Xiao Shuang was one of an estimated 16 million Chinese women married to gay men.

China has more than 20 million sexually active gay men, 80 percent of whom are married or will eventually marry straight women, according to leading sexologist Liu Dalin.

Women married to gay Chinese men are at greater risk of contracting AIDS as their husbands are among the most vulnerable group, experts say. Homosexual acts account for 32 percent of all HIV contractions in China, according to Ministry of Health statistics in 2009.

Chinese sexologist Zhang Beichuan recalls a gathering of 60 HIV positive people -- 40 were gay men and the rest were wives of gay men.

Zhang, who has been counseling wives of gay men since 1995, has found they are often subject to frequent and severe domestic violence.

Some gay people are distressed at being unable to be themselves, so they tend to vent their pent-up frustrations on their wives, Zhang says.

Painful break-up

When Xiao Mi, 28, who lives in Beijing, found romantic letters to men in her husband's e-mail, he moved out.

She had wanted him to deny being gay, but he admitted it.

Her 34-year-old husband promised he would change and stop his gay affairs.

"Every gay wife believes her husband is different from other gay men. I still had a thread of hope that he might change," Xiao Mi says.

The couple came together again, but their marriage was never the same. Xiao Mi was suspicious whenever her husband come home late. He no longer trusted her with his bank account and other assets.

Xiao Mi's suspicions were proven a month later when she thumbed through her husband's cellphone message box and found he had been frequently seeing gay men even after he promised to change.

She tore her wedding photo from the apartment wall and asked her husband to move out. She had made up her mind to divorce.

"It is the worst way to end a marriage. When a normal marriage ends, at least the couple had loved each other. But mine was just a lie," she says.

"Now, whenever I meet a man, the question 'Is he gay?' pops into my head."

A graduate of a prestigious Chinese medical college, she never heard about homosexuality at school. "I want people to hear my story so that others can avoid the same mistake," she says.