Rarity tried a potion at Zecora's hut, which was meant to make a pony younger and thinner. Unfortunately, the potion did the opposite for her after she consumed it incorrectly. Good News: it can be reversed by Spike. Bad News: she needs Spike's semen
I'm a shameless neckbeard who has a knack for writing a LOT of smut. I have an Official Patreon page (Patreon.com/TheVClaw), and I also take commissions to help support myself as a freelance writer.