Mathematics education research tends to center on what Mathematics Teacher Educators-Researchers (MTERs) work on or the people (teachers and students) they work with. Rarely, research in mathematics education focuses on MTERs working with one another. This article decenters from these traditional foci and instead examines a heterogeneous group of MTERs describing their research collaborations for professional development efforts on social justice issues in mathematics education. The MTERs' paired conversations focused on their retrospective stories of their collaborations were analyzed using an Anzaldúan framework to name the different spaces of collaboration that MTERs identified. Results provide insight into how MTERs' identified binarized spaces linked to their identities and compounded by issues of power. Nevertheless, MTERs also identified spaces where boundaries were blurred promoting a "nos/otras" space of collaboration. We discuss how collaboration reaches beyond doing the same research work and sharing talent but also understanding the work of one another.