Perhaps the best way to tactfully brush someone off when they are peering over your shoulder is to strike up a conversation about a mundane or personal topic for which you know they don't want to discuss.

"Ever notice this office smells like garlic and onions?"
"Did you guys ever get the house sold, or is still on the market?"
"You mentioned the other day that you voted for Trump. So, how do think he's doing so far?" :rolleyes:

Of course, if you can't tolerate your boss's management style, then it's probably time to polish up the resume and move on. All the extra special attention may actually be his way of pushing you out the door.