The presentation analyses a research-action in ethics and design conducted from and with the contextual realities of institutions for the elderly. It is from a shared disorder, emerging from the painful experiences of mourning during the COVID-19 pandemic, that a collective investigation is initiated into the modalities of accompanying this experience and the co-design of a support device. The situated and contextual approach leads to an exploratory process of the modalities and issues of co-design. Collaboration and participation lead to an opening up of the design by maintaining an unknown and the occurrence of potential deviations. From an internalist perspective of ethics, we will try to show that a practice of situated and collaborative design does not only allow to identify the needs of a situation and of the stakeholders, but also to allow mutual configurations to occur between the situations investigated and the project frameworks. We will first show the suspension of ‘interpretative routines’ (Sabel, 2012) through the meeting of the disciplines of ethics and design. Then, the emergence of a common commitment of the actors in a “collective inquiry” (Dewey, 1938). Finally, we will analyse the conflicts, misunderstandings and distancing that may have arisen, as moments of opening up the design to improvisation. This opening up of the process to a succession of affections and rearrangements by all the actors in the process contributes to a concordance between the design process and its output: the setting up of a device for facing up to the experience of bereavement.