he likes the taboo

my boyfriend and i have been together for five years now, but recently we started exploring some new stuff. he really likes roleplaying as a student teacher scenario with me playing his student, even though im actually ten years older than him. we agreed on it being consensual, clearly defined limits and safewords. the other day when hes teaching me something new in bed, he gets super into it, almost like hes not fully aware of the real boundaries anymore. i want to know if its normal for someone to get that immersed in a roleplay? im worried he might accidentally cross a line. what do you think? we really enjoy this dynamic but i wanna make sure everything is safe and consensual.