In the wake of opening the School of Friendship and Twilight seeking for more teachers, Fluttershy asks Discord if he would be interested. He said that he will do a test drive by teaching his students a lesson in Philosophy.
Tempest Shadow should be languishing in a prison cell, waiting for her punishment. Instead Twilight asks if she’d like to sleep with her- just for the night. This friendship thing might be more confusing than she thought.
You are...you can't remember, so lets just go with Anon. You are Anon, and you have arrived upon Equestria as the result of a magical spell cast by Twilight Sparkle...your new roomate.