step on a crack, break your mothers back

The other day we went to the store and Ellie was not being her 'best self' if you know what I mean, so we put all of our stuff down and walked out of the store. I recently learned this trick from Wade. Normally I would endure the freak out so I could buy what I had in my cart, now I just walk out. Turns out most of the time that I didn't end up needing what I was going to buy.
Anyway, we were walking across the parking lot to the car and she was all mad and whining about not getting whatever it is that she had to have. And I was lecturing her about the fact that she does not always get to get something at the store, especially when she is not behaving.
And while I am droning on and on, she is walking next to me saying "I'm stepping on every crack." I say "Why, so you can break my back?" And she says
"Yea, and I'm going to stand on this crack for hours."