Establishing a reciprocal relationship between mentors and pre-service teachers is critical in pre-service teacher mentoring. Highlighting self-regulation as a means for managing emotions in the pursuit of meeting long-term goals, this study examined the constructive features that help develop a reciprocal relationship between pre-service teachers and mentors. The study has captured a range of qualitative data from the dyadic process of mentoring (two-way interaction between a mentor teacher and a pre-service teacher): within the pre- and post-lesson conferences between mentors and pre-service teachers and post mentoring interviews with mentors and pre-service teachers. The study highlighted the strengths of mentor facilitated THINK4 reflective thinking to enhance professional learning: think ahead (at the preparatory stage), think while (at the performing stage), think back, and think forward (at the appraisal stage). The paper highlights the critical role that the reciprocal relationship plays in each THINK stage of mentoring to foster preservice teachers' self-regulation.