To my faithful student, Twilight Sparkle,
Happy Nightmare Night, my little pony. I'm sorry to hear about your costume difficulties. I do hope you didn't take the comments regarding weight too seriously. After all, ponies bodies do change over time, especially if you have a sedentary lifestyle. I myself had to take up going for a morning canter a few decades back. It's a shame your friends were either too blunt, or too kind to communicate the problem before it became an issue. There is a balance between being tactful and being honest, and I hope this gives you a better idea of where that fulcrum is.
Your loving mentor,
Princess CelestiaPS. Anon, I do not think that word means what you think it means.