bootie bump

Tonight Zander and I were doing word flashcards. He was working on the word "soon". He wasn't quite sure how to sound out the two o's, so I helped him a bit. I told him they sound like "ooooh" and he responded, "like bootie bump?!" and then bumped me from the side with his little bootie. I was laughing so hard and asked where he heard that. He said, "dad always gives me bootie bumps!"