This essay investigates how teenage boys respond to and perceive sex education taught in schools. It describes prominent patterns of response and suggests explanations for boys’ frequent rejection and disruption of courses using data and conclusions from a variety of studies. Hierarchies of masculine sexual power and position as well as the relationship between physical size and social capital are discussed. It is shown through evidence that arrogance and disruption are responses to sex education that ignores the requirements of boys. All in all, people must design learning situations where they can, if only briefly, set aside the need to act rigidly sex-stereotypically.