M.C.
If they ask, I would let them. Chances are he has questions or would like some privacy if he is getting a physical. I can't blame him... At 11, he is entering puberty and it's pretty normal that he wouldn't want anyone else there. I know I would feel awkward going to a gyno with my dad at that age... And it would have been weird with my mom as well. Some people are just more private, and I would allow him that independence.