The three way relationship within external supervision is complex and offers exciting possibilities. Three way relationships can be messy and misunderstandings about expectations and responsibilities ill defined. External supervision offers opportunities for exploring practice, professional development, and associated relationships. A supervision relationship external to the workplace allegedly supports best practice within the work setting. There are a range of understandings within service sectors about the dyadic relationship between supervisor and practitioner. We purport that there are fewer understandings about the ménage à trois of practitioner, supervisor, and agency (manager). This paper will explore some responsibilities in the relationship between the agency (manager), practitioner, and supervisor, and suggest some practices of accountability. Reflecting on our own practice as supervisors both within agencies and as external supervisors, this paper invites supervisors, practitioners, and agency (managers) to engage in thinking and reflecting upon supervision experiences and practices. Our intention is to critique, challenge, and support ways of developing useful and accountable external supervision practice.