Beliefs regarding the causes of nonheterosexuality are linked to acceptance of sexual diversity, pro-diversity aligning with ‘nature’ explanations and anti-diversity with ‘nurture’ explanations. The latter includes the idea that nonheterosexuality is socially contagious and will spread if prohibitions are relaxed. We focus on the concern in China that consuming female-oriented male-male erotica (‘danmei’ or ‘Boys Love’) may result in its audience eschewing heterosexuality. This provides a case study to test if pornography can impact sexual orientation and, if so, to understand better how, for whom, and under what conditions. We posit that the effect of pornography on sexual orientation, if it exists, is mediated by audience members’ social outlook and will be evident only in regions with low acceptance of sexual diversity. We employ the statistical modelling technique of Conditional Process Analysis, comparing results using data from our Sinophone (N = 2128) and Anglophone (N = 2001) audience surveys representing, respectively, conservative and progressive contexts. As hypothesised, the model was supported by the Sinophone and not the Anglophone data. We conclude that regions with low acceptance of diverse sexualities paradoxically create phenomena which look like the socially-contagious processes they are trying to stem.