Long association with a mathematics teacher at a Grade 4-6 school in Sweden, is basis for reporting a case of teacher-researcher collaboration. Three theoretical frameworks used to study its development over time are relational knowing, relational agency and cogenerative dialogue. While relational knowing uses narrative perspectives to explore the experiential and relational nature of collaboration; relational agency, draws on activity theory perspectives and identifies the change in the purpose of collaboration, from initially conducting classroom interventions to co-authoring research. Finally, cogenerative dialogue, deploys hermeneutic-phenomenological perspectives and investigates the dialogue that transpired between Lotta and the author, as they co-authored their research report. Such analysis sheds invaluable light on a case of expansive learning activity.