Establishing a genuine partnership is a prerequisite when service-users become co-researchers. The practices of co-research challenges conventional scientific communities to rethink research processes and to learn to develop a genuine participatory research culture. This analysis investigated how a research partnership was created by exploring small group collaborative processes in a cooperative inquiry dealing with an interview study about psychosocial rehabilitation of elderly individuals bereaved by suicide late in life. The analysis highlighted how reciprocity can facilitate "epistemic user participation" and promote a research outcome that is co-created in a genuine partnership that reflects the perspective of service-users.