How could you?

..."This is the map to our father! You had it the whole time? How could you? Well, you can go to the North Pole on your own! I'm going to find Dad." They are both outraged and hurt Aang just as much as he hurt them... except for one major difference, they hurt him with punches while he hurts them with words. The summary is really bad but hopefully the story is better. Please read!