Showing up for Racial Justice (SURJ) is an anti racist network in which mainly white activists participate in joint activity, the process of co-participation and co-learning in an effort to achieve racial justice. This paper focuses one chapter of SURJ in the greater Denver, Colorado area to examine the learning that emerges as critically engaged white people practice anti-racist organizing and reflective work. Grounded in sociocultural theories of learning and Critical White Studies, we draw on our own experience and Community Based Participatory Research (CBPR) conducted over one year, to examine how joint activity shapes meanings and the necessary social conditions for learning, in ways that lead white people to practice self-reflexivity on the individual, collective, and societal levels.