he has only done it here at home. usually while he's by himself watching t.v. cartoons. when we were doing something else at not there with him. thanks for the input.
does he do this in private? or public?
It is not abnormal my son did it also. He is 18 now and is very normal and doesn't do anything in public. He used to when he was little like 3. If you teach him where it is and isn't appropriate he should get it. Why stop it, then he will think it is a horrible thing to do.
If you can't get through to him have his doctor, a therapist talk to him about privacy.