Oh gosh, this is a hard one. Many autistic and sensory kids are rule bound. My son has sensory integration disorder and is this way. He will learn rules and follow them. Our OT is big on saying NO firmly. Rule is you can not touch that area in public. Period. So, you can make it a discipline issue if you need to. Have you tried that?
Is your problem that he does it in public, or that he does it at all? If he is not doing it in public, there really is no reason to be too worried, after all, he is 10 and hormones do begin rising pretty soon.
My son knew the difference between public and private very young, we just accidentally fell into that vocabulary, and it was very helpful on a lot of occasions. Private, to him, means only when alone in your own bedroom, with the door shut. He is 8 now and will (hilariously, to us) announce that he is going into his bedroom for some "private time" and we are not to disturb him (we assume it is so he can do some hands-on research about human sexuality, which is why we find it so funny that he announces it. He's beginning to be old enough to do it, but is still so young that he doesn't realize he's not particularly expected to tell Mommy and Daddy.) Anyway, if your son is only doing this in his room, I would not sweat it. He's going to anyway by the time he's 16.
anniebrooke, sensory kids sometimes do have an issue with touching themselves. They are sensation SEEKERS. My son is a sensory seeker. So, it can become an embarrassing problem for some kids. Just sharing the joys of sensory integration disorder. :) I have two boys and my other boy will 'adjust' as necessary like all boys but in occupational therapy, I was told that some kids will flat out masturbate on the soccer field to self soothe and calm themselves! I've never had to deal with that. But our OT is big on NO, not allowed. Depending on the level of the disorder, hopefully that will work for this child!
I agree that no means no, just was asking the original poster if she was saying it was happening in public or not. She didn't specify. (It's a different problem if he is or he is not.)
Did you ever find an answer? My 7 year old is having this issue now. He also is on the spectrum and has sensory processing disorder. He complains that it hurts and is very uncomfortable. He pushes it between his legs and after visiting many doctors we have no answers.