This article draws on data from a digital ethnography to identify a key paradox of Grindr, a gay hookup app. Despite the potential the app offers to invigorate public sex culture by circumventing increased policing of public spaces, users overwhelmingly use the app to arrange for sex to take place in the privacy of a home. Contemporary respectability politics in LGBTQ communities structures Grindr users’ reputation management practices as well as their perceptions of the purpose and potential uses of the technology. The porous public/private boundaries of the app allow users to navigate the stigma associated with promiscuity. "Respectable promiscuity" captures the negotiations individuals engage in as they enact stigmatized sexual practices, manage sexual reputations, and give meaning to their sexual practices within a specific socio-political context.