I am interested in the idea of Peter describing urethral sounding in some detail to Matt and Frank, and totally misinterpreting their groans. (I am also interested in the thought of Matt and Frank, sneakily or after they've driven Peter away, getting around to the long list of things he inspired in them.)

I also don't have a kink for prolapse or childbirth (circumcision only very rarely), but was thinking of the treatment/procedural aspects that are often such a large part of medical kinks.