Even when overt sexism and prejudice become rarer, social norms that perpetuate inequality are remarkably persistent. The present research lays out one of the subtle ways in which sexist norms may spread through society, by pointing to the role of responses to sexism. We investigate how third parties infer social norms about sexism when observing social interactions. In three studies among male students (Studies 1 and 2) and male and female students (Study 3), we demonstrate that subtle variations in how people respond to a sexist statement can have a substantial influence on inferences third parties make about sexist norms. Specifically, when a sexist statement is made and the conversation continues in a smoothly flowing fashion, third parties infer that this opinion is shared among interaction partners, perceived as appropriate, and that sexism is normative among them. However, when a sexist statement is followed by a brief silence that disrupts the flow of the conversation, observers think that it is contentious and that sexism is neither shared nor normative. Importantly, the effects of the manipulation generalized to the perception of sexist descriptive norms among male students in general. We conclude that social and cultural norms are not just inferred from conversation content, but also from conversational flow.