Wow, Twilight was very dominant in this story.
Sounds like she's in heat, though it's not mentioned in the story.
I appreciate the inclusion of her frantic/ manic attitude for being late. It's very in character for her.
I'm not sure if her demanding/ dominance side is due to the stress and panic she gets clouding her normally reasonable, intelligence, or if it's her being in heat which makes her behave as she does. Or if it's one of those things where the quiet librarian type turns out to be a real kinky dominatrix/ nympho during sex.
But, then again, that's the reader's curiosity, given how this story is told from Anon's perspective, it makes for better writing/ story, if we're not given an omniscient narrator/ 3rd person view of the inner workings of Twilight, so regardless of my incomprehension of Twilight's behavior, because you didn't lay Twilight bare for us, the reader, makes me consider this story well written from that aspect.