I have to stress that I do not think bear is trying to do anything. I think it is entirely accidental and without malice. It is also without much contrition.
Last night I was on the phone telling bear's cousin all about it. I stopped mid-sentence as bear paraded through carrying a piece of card with 'Shame' written on it.
I could hear giggling behind the cardboard as he held it in front of his face. I told this to his cousin who was highly amused, and updated her on the position of bear's thumb. Bear returned with this.
I reassured him that it would be very simple and he would be fine while continuing to chat to his cousin. Bear returned with the amended first sign.
I'm working on stopping him interrupting phone calls. At least it has stopped audible interruptions, although the giggling kept going.
Bear does continue advanced. For a nine year old, his eye rolling at what his parents are telling him is remarkably forward. At the moment I find the roll of the eyes amusing. Long may that continue!