Imprisoned sex offenders face abjection because of their criminality and are the most victimized group of adult male prisoners. Drawing on Judith Butler’s work on gender, abjection and precarity, and scholarship focused on prison masculinities, we examine the experiences of sex offenders while incarcerated and the role of various agents in exposing their convictions to other prisoners and, ultimately, to victimization. Given each prisoner’s convictions are not immediately known when they enter the penitentiary and recognizing that prison is unsafe for sex offenders, we sought to understand how sex offenders attempt to pass among the general prisoner population and the methods through which their convictions become known. Utilizing interviews with 59 formerly incarcerated men, we analyse the modalities that sex offenders employ to ‘pass’ as non-sex offenders and the anxieties associated with awaiting their inevitable exposure. Former prisoners reveal the methods used by staff and prisoners to expose those with sex-related convictions.