Middle Boy is INSISTING nothing is bothering him.  You can see it in his face and in his body language.

I asked him a couple of times, but he insisted there was nothing.  I finally said "Liar, Liar, pants on fire" and he laughed and told me he had gotten into an argument with one of his friends and that he really felt bad about it.  He thinks he needs to apologize tomorrow.

Communication...it is improving.