"His head fall off"

I was driving around town yesterday with M and J in the backseat when out of the blue she says, "His head fall off." Ummmm...what? I asked her to repeat what she had said and sure enough, according to her, his head had left his body. When I could safely check out what was going on, his head had just rolled onto his chest. (I know you were worried.) I helped prop him up, but must not have done a good job because minutes later M reported his head had fallen off again, but this time she burst out laughing. It became a game. I could not seem to situate his head so it wouldn't "fall off" so every time it rolled M would tell me, laugh, I would reach back and help, and then the process would start all over again. I was really glad to pull into the garage because those were some of the longest errands I have run in a long time.