Mad at You!

So the other day when Kara had left the kitchen after dinner I was supervising the boys so that we didn't end up with a monster mess in the kitchen. Out of the blue, Christopher says "I going to be mad at you guys!" Perturbed by this Nathanial says "Why are you going to be mad at me? I didn't do anything to you. I've been nice to you. You shouldn't be mad at me." In reply Christopher says, "OK Nathanial, I not mad at you." He then turns to me and says, "Daddy, I going to be mad at you!"  Trying not to laugh at the the conversation that has just taken place I ask Christopher, "Why are you going to be mad at me?" To which Christopher says matter-of-factly, "Because, I not going to be mad at Nathanial."