This was HUGE.
First, he actually noticed the social norm: parents don't stay for these talks.
Then, he made a conscious decision to conform to the social norm: other kids don't have their parents stay, and I want to be like them. He used very similar words to this, actually.
This child has been largely oblivious to social and behavioral subtleties for most of his life--when you have to struggle mightily just to understand the language going on around you, all else becomes secondary by necessity. It is a measure of how far he's come that he is starting to pay attention to what others do, and to what they think of him. (He was not happy about having to wear his basketball shoes to school until one of his classmates told him that they looked cool, and then he was fine with it.)
And the icing on the cake was that he knocked his poster presentation out of the park. Bless his teacher, I didn't even ask her for feedback, but she emailed me the following this afternoon:
"He did an awesome job presenting his poster! He was confident, proud and very happy. He also did an excellent job answering his classmates' questions. He is really flourishing this year!!!!!!!!!!!!!!!!"
I think I might cry. It's been a long tunnel, but I see light.