South African Men Who Have Sex With Both Men and Women and How They Differ From Men Who Have Sex With Men Exclusively.

The label "men who have sex with men" (MSM) is used to categorize a diverse population exclusively on the basis of its sexual behavior. Understanding the diversity that this label comprises is critical for the development of health interventions that effectively reach the various populations subsumed under this label. In this cross-sectional study of South African MSM (N = 480) recruited through respondent-driven sampling (RDS), we explored differences between men who had sex with both men and women (MSMW) and men who had sex with men exclusively (MSME). We found significant differences between these two groups in terms of sexual attraction, sexual identity, sexual preferences, sexual histories, and current sexual practices. MSMW were more likely to be confused about their same-sex attraction, to experience internalized homophobia, and to have paid for sex in the previous year, while MSME were more gender nonconforming and more likely to have been forced to have sex in the previous year. These findings underscore that the MSM label comprises a diverse population and that exclusive sexual engagement with other men is a critical distinction to take into account in understanding this diversity and fully grasping the lived experiences of men who have sex with men.