When Celestia comes to Ponyville for a visit on some royal business, she bumps into an excited and adorable little unicorn looking for a Princess to be at her tea party. Celestia, always working all the time, decides to relax and play along, letting
Everypony thinks that Celestia is called 'Sunbutt' because of her cutie mark. Only Luna knows the real story, though, and now she's going to share it with Twilight.