THIS COULD BE ME

Sorry, but it's in swedish and their is not english subtitles, so you all can understand.. But I'll sum it up for you guys. 

He gets mad when he can't fit the cookie in the glas of milk and starts overreacting. What the other boy is trying to explain is that he can split it in two, but not really succeeding. I think you'll figure out the rest by yourself, the body language is not to hard to read.
Haha, this could so be me!