He sees the toothbrush coming and is instantly flat on his face to avoid it.
When I don't fight him right away, he's curious why not and discovers I have the camera out.
I haven't gotten the shot yet, though, so I hold up the toothbrush again and he whips back into position. Over and over again. Camera, curious. Toothbrush, face down.
I get the shot in the end, and I get his teeth brushed, too.