In public settings Middle Boy's behavior becomes VERY YOUNG.

At the pool party he was fine.  At the dinner afterward he was throwing pens, running, tackling other kids, and yelling.

Really?  How many other kids are doing that?  Oh...just you and the one you instigated into it?  Hmmm...that's odd.

On the way home we talked about it.  We talked about how that isn't appropriate.  It isn't appropriate indoors.  It isn't appropriate in a public setting.  It isn't appropriate when you are his age.  It isn't appropriate...period. 

His response...at least I waited until some of the people had left.  No...INAPPROPRIATE....ALWAYS.

He doesn't get it.  We are going to have to address it again.