This article explores the legal and judicial vulnerability of male youth in Buenos Aires, Argentina between 1853 and 1912, years that correspond to the codification of criminal law and the passage of the first age of consent laws. Using 65 sodomy and rape cases, it traces the courts' changing treatment of males who suffered sexual assault. It argues that a traditional revulsion of sodomy, a cultural preoccupation with female sexuality, official concern with the social order, and the preoccupations of classical and positivist criminologists ensured the liminality of male youth in both the law and the courts. Judicial authorities only started to regard prepubescent boys as innocent in the first decade of the twentieth century. By highlighting how age, innocence and gender were only mutually constituted in the twentieth century, this article makes a significant contribution to literature on the emergence of modern notions of childhood and innocence. Historians have shown how categories such as class, ethnicity, filiation and natal status worked to include or exclude certain groups from this classification in modern Latin America, this work reveals how central both age and gender norms and expectations were to the belated integration of boys.