When people violate certain social role norms, they risk false categorization into a stigmatized group. For example, heterosexual men who perform female stereotypic behaviors are often misclassified as gay. This identity misclassification is aversive because it threatens fundamental psychological needs. Findings presented here reveal that expectations of identity misclassification fuel heterosexual actors' (N=216) discomfort during imagined gender role violations and that audience variables that increase the likelihood of misclassification also increase role violators' discomfort. Moreover, expectations of misclassification strongly predict people's discomfort during gender role violations regardless of their standing along relevant actor dimensions (e.g., attitudes and self-views). These findings suggest that people's-and particularly heterosexual men's-expectations of identity misclassification are powerful mechanisms that underlie adherence to traditional gender role norms.