Twilight Sparkle has a sudden obsession of fanfiction, and attempts to write her own. She later gets the mane six to act it out for her in a play - in front of the Princess! As she goes through a "Psycho Twilight" phase, she later realizes she is not cut out to be writing fanfiction, and learns a new lesson about being herself.
Rated Everypony, but there are some adult themes in Twilight's fanfiction. (However, when the ponies act it out, it is all a fake. For example, AppleJack and Rarity don't actually kiss, but fake it instead.)