I heard “Sliver” by Nirvana on the Regina community radio station this morning and it made me think of Pace's current trick.
He now understands that Shea sometimes leaves the room or isn't in his line of sight. He still doesn't understand that she always come back. So as soon as it happens, he FREAKS OUT!
It's to the point that the other day, I felt obligated to tell Shea, “just so you know, I don't start beating him as soon as you leave the room” when she popped out to the kitchen to get a drink.
(Man, I hope this is a phase and that it passes quickly!)