Nonmonogamy is undertheorised as site of anticapitalist resistance, despite monogamy’s intimate connectedness to Capitalism. The purpose of this study is advocating for conceptualising resistance at its broadest by including the personal realm as political. Nonmonogamy is mobilised as both sex-affectiveness and socio-political organisation to highlight the inseparability of sexuality and the political economy. The text lays down a theoretical background on the need to recover the 70s Feminist slogan the personal is political to challenge the liberal and sexist ontology of private vs public that brackets social life and political activity. The study is driven by the tendency to downsize aspects linked to the personal realm as not politically relevant within the wider framework of social movements, and by an apolitical, privatised and sexuality based approach to nonmonogamy in written production. The risk of neoliberal co-optation of antinormative sexualities’ political agendas is also a driving motivation. Using activist feminist ethnography, this study centres around the reflections of six anticapitalist activists identified with nonmonogamy and engaged politically in the Spanish state. It uses semi-structured interviews and thematic analysis to gain understanding on how nonmonogamy is articulated vis a vis the activists’ political engagement, and on to what extent the personal is given political significance and mobilised as an anticapitalist strategy.