Recently Feminist New Materialism has emerged as a field that questions the capability of critique to offer substantive change and calls for more affirmative forms of criticality which add to, rather than subtract from, alternate ways of living in the world. This ‘affirmative turn’ is an emerging influence in social work where it is taken up to disrupt human-centred notions of agency and engage with the non-human and more-than-human relations that make up the material-social world. This paper adds to this work, utilizing Karen Barad’s concept and method of diffraction to critically engage with trauma-informed practice, a current popular approach in social work that draws on neuroscience and social theory. Specifically, diffraction is used to put neuro-trauma theory into conversation with Extended Emotion theory, and through reading the insights they offer, re-configure trauma-informed social work as situated, embodied, relational practices for making differences that matter in the world. This example also suggests what diffraction makes possible for social work as an onto-ethical mode of affirmative critique.