Almost 10% of men self-proclaimed straight men had had sex with at least one man during the last twelve months, reveals a new study carried out by the New York City Department of Health and Mental Hygiene.

70% of men who had a homosexual experience were married. Many of these men said they had not used a condom and had not been tested for HIV.

Even more, straight men who had had sex with another man were less likely to use a condom than gay men in similar situation.

Study based on a survey of nearly 5,000 men, also found that men who had sex with men exclusively but self-identified as heterosexual were more likely than their gay-identified counterparts to belong to minority racial or ethnic groups, be foreign-born, have lower education and income levels, and be married.

This study shows that doctors cannot rely on patients' self-reported sexual identity to assess his risk for HIV infection and sexually transmitted diseases. Doctors also must inquire about his actual sexual behavior and assess the risks accordingly.