A Beijing lawyer who defends the rights of "er nai," or mistresses, might need some defending himself.
Four months ago, Zheng Baichun set up a Website offering legal advice to women in relationships with married men. Over 100 mistresses have asked for his help.
He believed mistresses are vulnerable as many are from poor families.
Zheng's wife apparently didn't share the lawyer's commitment to his cause and she has filed for divorce.
For his cause, he says any unmarried woman who has a stable sexual relationship with a man and receives financial support from him has legal rights that need protection.
His Website and his ideas have led to some harsh criticism. It is not unusual for rich Chinese men to keep mistresses who often draw criticism for corrupting public morals.
Zheng said mistresses are often afraid to rely on the law to safeguard their rights which can be undermined by society's moral standards rather than ruled by law.
Zheng's Website has received more than 36,000 visits.
He has helped four women so far. In one case he helped a woman win child support from a man who fathered her son 13 years earlier.
Guo Huimin with the Northwestern Polytechnic University said the legal rights of mistresses should not be denied. "Moral wrongs and legal issues should not be confused," Guo said.