My daughter speaks up on their behalf, so you're correct, I do not usually get involved. A few weeks ago I told him to "knock it off" when he had my grandson by the waist, upside down and shaking him, when my grandson's face started turning red and his eyes were rolling back in his head. I also told him that I was going to do the same thing to him to see if he thought it was "fun", because, again my grandson was laughing. It didn't go over well, but I was the only one around, so I decided to intervene.

Luckily, he does not have the children by himself ever because of issues in the past as well as his narcolepsy, but he's completely oblivious to their experience in almost every situation. I can't tell if he's as dumb as he seems or just wilfully ignorant.