Sexual activities and condom use among heterosexual men and women engaged in mixed-gender group sex events in Melbourne, Australia.

BACKGROUND:Few studies investigate group sex among heterosexuals. The aim of this study was to provide an exploration of characteristics and practices among heterosexual men and women who engage in group sex. METHOD:We conducted a cross-sectional survey between May 2019 and March 2020 among heterosexual men and women attending a sexual health clinic in Melbourne, Australia. Participants were asked whether they had participated in group sex (sex involving more than two participants) in the past 3months, the size of the most recent event, sexual activities in which they engaged, and condom use. RESULTS:Of 3277 heterosexuals surveyed (1509 women and 1768 men), the mean age was 29.9years (s.d. 8.8) and more than half (56.0%, n =1834) were born outside Australia. One in 20 participants (5.4%) had engaged in group sex in the past 3months with the number of events ranging 1-10times. Kissing was the most common activity in group sex, and women were significantly more likely to kiss a same-sex partner than men. Overall, of 165 participants who engaged in vaginal sex, 57 (34.5%) reported always using condoms and changing condoms between consecutive partners. Of the 100 men and women who had condomless vaginal sex, 79 (79.0%) received or performed fellatio after condomless vaginal sex. CONCLUSION:About two-thirds of heterosexuals who engaged in group sex neither used condoms nor changed condoms between partners in the most recent group sex event. Safe sex messages on changing condoms between partners and between sexual activities should be reinforced for sexually transmitted infections prevention.