This study advances a concept of science religion encounter (SRE), with preliminary theorisation and shares findings on the extent and nature of such encounters reported by secondary religious education and science teachers. SREs are interdisciplinary engagements in classrooms involving subject knowledge from more than one subject. The researchers hypothesised they may arise unexpectedly, when a pupil asks a question, or be teacher-planned and intended. This article further elaborates the concept of SRE with reference to the concepts of 'epistemic trespassing' (ET), epistemic neighbourliness, and overlapping domains, introducing these to the field of education. The study is contextualised in the school classroom with quantitative data gathered among beginning and experienced teachers measuring whether this ET in SRE topics enter the classroom via 'spontaneity' or via a 'deliberateness'. This clarifies the different roles a teacher may play and offers considerations for teacher development when navigating an SRE in ways that potentially reduce lost learning.