Well I have a very silly DS4 (almost 5). Not quite like yours in that he doesn't act things out and pretend...he just acts very silly, immature and annoying sometimes. It's not consistent, and is somewhat based on his environment. He also goes with the flow. If one kid starts to scream and run, he is right behind them. he is getting much better about this, but it's still there. So in his class at church he acts out often, saying silly things, making noises during prayers, etc. At his Montessori school he is a perfect angel. No problems at all. At home, it depends. He behaves and is appropriate most of the time, but has his moments where he just makes lots of noises, sounds, funny words, etc. He tries to baby talk with his little sister which is quite annoying as well when he just won't stop. We find it all odd at times, but have found that he tends to do this more when he just doesnt' know what to do with himself. If we give him something to do it almost always goes away. Anyhow, we are hoping he grows out of it eventually. He is maturing in many ways. And if he is with older kids doing different things he is quite mature.
But what you are describing sounds fairly typical of a child that age. Regarding the OT, most kids can really benefit from those services. But if he is having problems with this particular person that could be a problem.
I will check on books. I do have some recommendations,but not on me. I have a list we got from the psychologist that tested us about books like that. And also books specifically for boys that are gifted. Will post tonight.
