I speculate that it's partly him really settling into the routine of our house, partly my learning to read his body language better, and partly us compromising our behaviors. Regular playtime 3+ times a day really helps! (A few minutes before I go to work, a few more when I get home, and before I go to bed at minimum)
This was more common about three months ago, but it can still come up once in a while if I'm too busy to give him enough exercise. Not that he needs much, and it's definitely treat-motivated, but it's definitely good for him. He's lost a lot of the tubbiness he had when he first arrived, too.
Play With Me Stage 1: pointed stare from across the room
Play With Me Stage 2: face rubbing on nearby objects and leg
(this is usually where it stops these days; the more playtime he gets on the regular, the more patience he seems to have)
Play With Me Stage 3: teeth placement (not hard)
