The other day after a class a small child came up to me and patted my ass. I just sat there thinking "What the fuck was that about?" as I watched her go back over to her mother, say something in Japanese, and then come back over and do the same damned thing as the mother just watched.
Oh, and during one class with some young students (4-5 years old) a boy went over to his mother, sat in her lap, spread his legs, grabbed her hand and started using it to stroke himself off through his shorts. And yet, I was the only one in the room with a "OMG WTF!" expression.