Commissioned by: Anon, hailing from the land of Ymous.
Cover art from derpi: https://derpibooru.org/profiles/Cabrony

Twilight has accidentally told Rarity, of all ponies, that she has never kissed another pony. When Rarity offers to help, Twilight kindly rejects her, being a filthy "straight" mare(not actually an adjective ever used, thought it was funny); then Rarity takes advantage of a strange necklace the princess brought to her, and teaches the mare a solid lesson.

Contains subtle hypnosis, and cunnilingus.