Halvesies

Today...
Isaac: "half mom and dad, half!"  While patting his right butt cheek.
Me:  "half what, Isaac?"
Isaac:  "half-a-bum-bum!" 
Me: "where's the rest?"
Isaac: "other half-a-bum-bum!" While patting his left butt cheek. "Two halfs!!!!"

I never imagined he would be teaching himself about halves, and learn his first fraction, via his "bum-bum."  Let's just hope he doesn't demonstrate a "whole" moon or a select one fifth of his fingers anytime soon.