Of the increasing number of initiatives setting out to challenge heteronormativity in education, the "No Outsiders" project has arguably been one of the most influential. Conducted across 15 primary schools in England, "No Outsiders" sought to disrupt heteronormativity through critical pedagogy, gaining widespread academic and media attention in the process. In spite of its prominence, though, there has been a lack of research exploring the effects of this project on children's attitudes towards sexuality in school. This paper draws on data from an ethnographic study of two UK primary schools -- one that was and one that was not involved in "No Outsiders" -- to explore the 'effects' of this critical intervention. The research found that whilst homophobia persisted across both schools, children's understandings of its "acceptability" differed markedly according to their involvement in equalities pedagogy, with institutional silence interpreted by many as equivalent to school-sanctioned homophobia. The implications of these findings are significant, revealing proactive sexualities pedagogy as essential to countering the damaging effects of institutional invisibility.