Abstract
INTRODUCTION: Researchers have investigated group sexual encounters (GSEs) as potential sources for HIV/STI transmission among men who have sex with men (MSM); however, much of this work has focused on organized sex parties. AIM: To compare behavioral and social characteristics of groups of men who engaged in three types of GSEs: threesomes, spontaneous group sex, and organized sex parties. METHODS: In 2012, 1,815 U.S.-based MSM completed an online survey. MAIN OUTCOME MEASURE: We compared men based on their most recent type of GSE: threesome (68.2%), spontaneous group sex (19.7%), or organized sex party (12.1%). RESULTS: Using multinomial logistic regression, with type of GSE as the dependent variable, MSM who were HIV-positive, used stimulants (cocaine, methamphetamine, crack), consumed five or more alcoholic drinks, and reported receptive unprotected anal intercourse (UAI) during the most recent GSE had significantly higher odds of having had spontaneous group sex as compared to a threesome. MSM who were HIV-positive, not in a relationship, and did not report receptive UAI during the most recent GSE had significantly higher odds of having attended an organized sex party as compared to a threesome. MSM who were in a relationship, had consumed five or more alcoholic drinks, had used stimulants, and reported receptive UAI during the most recent GSE had significantly higher odds of having had spontaneous group sex as compared to an organized sex party. Compared to others, those having engaged in a GSE were more likely to report recent UAI (65% vs. 45%). CONCLUSIONS: Men having engaged in a GSE were at greater risk for behaviors that transmit HIV and STIs. Unique social and behavioral characteristics inherent to threesomes, spontaneous group sex, and sex parties highlight the need to identify prevention strategies to help those who participate in GSEs reduce their risk for HIV and STI transmission.