"She likes him so much. She asked if she could kiss his hand but was rejected and got very frustrated," he said. "She has no idea about her body, so she can't help displaying her sexual impulses."

He said his daughter has never received sex education. "I don't know how to teach her. I don't think she can understand."

A male patient at the rehab center sometimes masturbates in public and grabs at women, Fang Yuxiang said.

"Usually the social workers yell at him, or even beat him," he said. "Worse, people think he is a pervert and curse him. No one thinks of teaching him."

Sexual health expert Fang Gang said mentally disabled people are capable of participating in sexual relationships despite many factors — a reduced ability to make proper sexual decisions, for example, and the need for safe sex.

"The right approach is to help them distinguish between public and private behavior, instead of stopping such behavior and shaming them," he said, adding that with good education and counseling they can benefit from affection and intimacy.

Cai Cong, 26, has been blind since birth and attended a special-education school in Changchun to study massage.

He said he had talked with friends about sex, but it was considered "dirty talk". He said that some had never even heard of condoms.

For a long time Cai and his friends listened to a sensual radio program, which the government later canceled, saying it was pornographic.

Vulnerability

Adults with mental disabilities are rarely educated on how to protect themselves and are extremely vulnerable to sexual or physical abuse, said Li Lan, a program officer in Nanjing with Marie Stropes, a sexual health NGO based in Britain.

According to media reports, in 2005 an orphanage in Jiangsu province performed hysterectomies on two mentally ill teenage girls because the owner thought it would be too much trouble to care for them when they started menstruating.

"People with speech or sight problems easily fall victim, too, because abusers are confident their targets can't describe or recognize them," Li said.

Sun He with Handicap International said the biggest problem facing NGOs that want to solve the problem is a lack of professionals who understand the nature of disability and sexuality.

"Not enough attention has been given to this field," she said. The lack of research adds an obstacle to the organization's plans for next year to provide sex education to disabled people.

"Deep down, the problem is not simply that the disabled are not having sex," said Lyu Fei, CEO of the Able Development Institute, a Beijing NGO. "It's that they are still excluded from mainstream society, not only in employment and education but also in terms of sex life," she said.

"Not one of those issues can be addressed individually."