This paper presents specific elements of a much larger ethnographic case study of a group of five male friends between the ages of seven and eight years. The study sought to examine the ways in which the group’s social dynamics interacted to define, regulate and maintain dominant and collective understandings of masculinities. Dominant peer culture was found to be particularly potent in championing a hegemonic masculinity embodying and cultivating physical domination, aggression and violence. These understandings were interpreted as governed by the boys’ investments in perpetuating the masculine/feminine oppositional binary within a framework of patriarchal heterosexuality. In presenting elements of the study’s data, this paper illuminates that these boys’ understandings of patriarchal heterosexuality were significant in their construction and regulation of particularly limited and restrictive understandings of themselves and others. Against this backdrop, the paper provides further warrant for working with boys’ peer cultures within the early childhood context to deconstruct the interrelated and mutually reinforcing gender and (hetero)sexual binaries. It is argued that this deconstruction will enable a facilitation of boys’ exploration of alternative and less oppressive ways of expressing their collective masculinities.