So here's what happens. I meet him at his facility (it is one of those spa places where you can rent a room so you'll find independent hairdressers, barbers, massage, etc) and he asks if I have any problem areas. He then leaves the room for me to undress and get on the table under the sheet and blanket. I've started to undress with him in the room before (just shirt and socks and shoes) and he didn't flinch. I have also tried to have my full back undraped when he comes in the room but he just covers me up. I get he has his rhythm of rubbing through the sheet, then uncovering, then covering back before moving to the next place. Having said all of that, I don't know when I would bring up forgoing the drape. Maybe just mentioning that I am hot and then say something like what you wrote above.
Also, you guys KNOW the first place I am going if something does happen! RIGHT HERE!