It scared me to death.
First, I felt in his mouth to make sure there was nothing in there and then, as it KEPT happening, I turned him over on his back and opened his mouth . . .
. . . and lo and behold, he had a piece of his kibble stuck between his gum and floppy lip that he couldn't get to and it was driving him nuts.
After I helped him get rid of it, I laughed so hard I had to sit down in the middle of the floor. My children thought I was losing my mind! Hee hee . . .