Mate-choice copying is a mating strategy wherein women rely on contextual information to assist in securing accurate assessments of potential mates. Mate-choice copying has been extensively studied in non-human species and has begun to be examined in humans as well. Hill and Buss (2008) found evidence of opposing effects for men and women in desirability judgments based on the presence of other opposite-sex people. The current study successfully replicated these findings with 73 and 44 heterosexual men and women, respectively. Heterosexual men exhibited the desirability diminution effect, and heterosexual women exhibited the desirability enhancement effect. The current study also extended these findings to include 73 gay men and 32 lesbian women. Findings for gay and lesbian participants were inverted compared to heterosexual participants. Gay men exhibited the desirability enhancement effect, and lesbian women exhibited the desirability diminution effect, revealing sex differences in mate-choice copying spanning different sexual orientations.