Simple misunderstandings can lead to major consequences, as learned by Luna a thousand years ago with her banishment. Should've thought out those foalnappings better...
It's that day. The one day of the year that Celestia dreads more than anything in the world. And too bad for her, everyone seems intent on making her go through such an awful occasion. Well, at least she gets cake at the end of it.
Luna, strangely enough, receives a letter from Princess Twilight Sparkle. From the letter she can discern two things. One, Twilight definitely has a drinking problem. Two, she really loves her. And a third can go to being extremely kinky.
Celestia receives yet another letter from her faithful student, Twilight. Except this one doesn't include any lessons about friendship like she was expecting. Only drunk ramblings of a very intoxicated mare. May or not be truthful.
People like Button's mom. Some really, really like her. So it's no surprise a few fanart and stories are made in her favor. And now poor Button has to deal with the end result for some inexplainable reason.