Medical students are often faced with an ethical dilemma within the clinical setting--to learn from as many patients as possible but to learn only with consenting patients. Although studies have examined patients' and students' views about informed consent, none have examined how medical students talk about consent-related behaviours in "naturalistic" focus group settings. This paper aims to explore medical students' explanations of behaviours relating to patient consent. Thirty-five excerpts across eight focus group discussions were identified using what we call "momentum analysis": an identification of where the impetus of the groups' discussions changed noticeably. Ten were related to consent issues, seven of which occurred in focus groups with medical students. Utilising Malle's folk conceptual theory of behavioural explanation ("2004. How the mind explains behavior. Folk explanations, meaning, and social interaction." Cambridge Massachusetts: MIT Press) within a narrative framework, we identified seven types of consent-related behaviour across the seven excerpts and 101 explanations for these behaviours by students. We found that students employed less reason explanations but more causal history reason (CHR) and enabling factor explanations than is found in other studies of naturally occurring talk, suggesting that consent-related behaviours were difficult and that our students actively managed others' impressions of them and their behaviours. Although our data is generally supportive of Malle's folk conceptual theory of behavioural explanation we suggest potential developments to this theoretical framework following our analysis with naturally occurring talk. However, further research is needed with larger samples of behavioural explanations to contribute more fully to theoretical development.