It's really important for our kids to experience new things even if the cost of that is greater for us (i.e. meltdowns, embarrassment, judgemental people), than it would be for parents of NT kids. We walk a fine line every day between letting them grow and avoiding known triggers. We really earn those mother's day cards! You are brave and right to let him go and even if something happens, console yourself with the knowledge that he grew a little bit today and move on. My ds came in the room last night and said "next weekend we should try to do something we've never done before." I was impressed by how much he has matured since his dx. Of course when I asked him what he wanted to do he said "lets roll around in one of those huge hamster balls, that looks like fun". UUUggghhhhhh. Let me get the yellow pages.....
This kind of thing can wear a hole in your gut from worry.
He had fun at the fair.