I agree with Bulklover, it didn't happen with me at the beginning of the session, but if you click and one thing leads to another, I've been in sessions where both the dominant sessionette and yours truly went nude. It can happen on a first session, but definitely if you are a regular with some ladies I've seen. Debra D'Andrea, mentioned earlier, was one in my two sessions with her. I won't mention others who have not been written about here, but definitely more than a few in my years in the scene.
And I agree with crazycrazy and boyofwinter, "this happens more often with bodybuilders who offer wrestling sessions" as CC pointed out. My sessions have all been role play with one-sided non-competitve wresting, the "beast" being captured, etc. And as boyofwinter said, "be polite with your hands in whatever outfit she choses to start out in, taking care to groom yourself nicely in preparation for meeting her, giving the impression you're genuinely impressed by her physique etc." I'd add be polite and get groomed like you're going on a date. Yes, it is business transaction, but it's very personal. Good grooming and being polite never hurts. If you speak with the sessionette about muscle worship or body worship in setting up the appointment, and they either say yes or a provisional yes... good things can happen.