The widespread nursing interpretation of clinical supervision following the accepted definitions of Butterworth and Faugier, elides refinement of boundaries between personal and professional development and growth. In so doing, nursing interpretation confuses the differences between two similar processes and ultimately distorts the purpose of clinical supervision. In nursing supervision, the patient can become lost, thus perpetuating the avoidance of anxiety in intimate therapeutic work, originally described by Menzies in 1959. While a tension naturally exists between the two processes, this paper demonstrates the utter importance of working within the tension of boundaries that define the triadic situation of supervisor, supervisee and patient. When supervision is accepted as personal development, the triadic situation may deteriorate into a dyadic one between supervisor and supervisee only, significantly altering the relationship to the point where the supervisee becomes a patient. Parallel process, ordinarily reflecting the therapeutic nurse-patient relationship in the supervisory one, may then become merely a process running parallel to the supervisee, while utilizing the patient as a source of material for personal growth. This paper demonstrates through Faugier's casework material the necessity of defining boundaries and the difficulties associated in maintaining them, rather than prosaically declaring that 'supervision is not therapy'.