My children get a pretty regular diet of Your Story Hour. (If you don't know what that is, check out http://www.yourstoryhour.org/.) A lot of these stories feature kids in school, sometimes even high school, so I guess shouldn't be surprised at some of the more mature content of their imaginary adventures.
Yesterday at supper the boys were pretending they were in high positions. "I am a king!" Seth boasted.
"Well," retorted Skyler, "I am a principal!"