Gosh, it does sound like it was pretty harmless AND the guy also seems to have proven himself already for a long time.
Maybe you want to pose it as a semi-question? Say something like: "in our last appointment you seemed to retract DS's foreskin a bit and it has been on my mind because all that I have read AND what you've always explained to me is that one shouldn't even touch it. Can you explained why you did that?"
Then maybe say "It made me unconfortable. Could we leave his penis out of future examinations?"
Given his approach to medicine it seems he'll have no problem. I'm sure you can word it very kindly.
Maybe you want to pose it as a semi-question? Say something like: "in our last appointment you seemed to retract DS's foreskin a bit and it has been on my mind because all that I have read AND what you've always explained to me is that one shouldn't even touch it. Can you explained why you did that?"
Then maybe say "It made me unconfortable. Could we leave his penis out of future examinations?"
Given his approach to medicine it seems he'll have no problem. I'm sure you can word it very kindly.