J Theor Biol. 2021 Jul 9:110832. doi: 10.1016/j.jtbi.2021.110832. Online ahead of print.ABSTRACTThe epidemiology of sexually transmitted infections (STIs) is inherently linked to host mating dynamics. Studies across many taxa show that adult sex ratio, a major determinant of host mating dynamics, is often skewed - sometimes strongly - toward males or females. However, few predictions exist for the effects of skewed sex ratio on STI epidemiology, and none when coupled with sex biased disease characteristics.