This paper reports on a research project that heard the perspectives on and experiences of the Relationships and Sexuality Education (RSE) programme of a range of stakeholders in post-primary schools. The researchers listened to students aged from 13 to 18 years, to teachers of RSE, to principals and to parents/guardians in six post-primary schools across the Republic of Ireland. We found that teacher comfortability is one of the key components in the delivery of high-quality and effective RSE. By 'comfortability' we mean knowledge, expertise, confidence and appropriate pedagogical skills to teach this particular material. This view was shared by students, teachers, principals as well as some parents who commented on this aspect of RSE. We found that there are several factors that impede teacher comfortability, namely lack of qualification in Social Personal and Health Education/RSE, lack of initial teacher education input in this area, limited access to continuing professional development, an absence of mandated curriculum content and fear of external criticism especially by parents. Our findings are very similar to those of the NCCA [2019. Report on the Review of Relationships and Sexuality Education (RSE) in Primary and Post-Primary Schools. December. Dublin: NCCA] evaluation that took place in a similar time-frame and included a similar range of participants.