Twilight's smart enough to have nothing to do with Rarity and her gang of delinquents. But as her world view is challenged and as Rarity takes interest in her, slowly Twilight finds herself getting closer to Rarity and becoming a delinquent herself.
What do you do when you're ridiculously fertile? As in '95% chance of pregnancy for every intercourse, minimum'? For Celestia, she handles it like she does every other problem: make it somepony else's.