The study explores inter-professional collaboration between a teacher educator (TE), and preservice teachers (PSTs) and a co-teacher (CT). The co-teacher is a practising schoolteacher employed part-time by the university due to expert skills in managing challenging behaviours. The main aim of the study was to answer Master of Teaching PSTs anonymised survey responses indicating the need for support when working with students in school classrooms displaying challenging behaviours. The concepts of 'relational expertise', 'common knowledge' and 'relational agency' (Edwards 2017) have been drawn upon to understand ways practitioners from intersecting practices can expand their understanding of a problem by using their specialist expertise and working together to inform joint goals and future directed actions (Rickinson & Edwards, 2021).