After the story: The princess got absorbed in getting the prince to teach her new games and was enjoying herself, but later was rather embarrassed to learn that these were things one did when playing with a dog, and so she got angry. The prince had only intended to tease her for a little bit and then tell her, but in the end, he was so happy to be able to be with the princess and play with her that he wound up forgetting himself
.... It's that kind of manga. :-)