A Canterlot Wedding - Part 1

S2, E25: The ponies are summoned to plan a wedding for Shining Armor, Twilight's older brother and captain of the royal guard at Canterlot, and Princess Cadance, her childhood friend. Twilight becomes suspicious of Cadance when the princess fails to remember her, and even more so when Cadance continually puts down all of her friends. When her friends refuse to listen to Twilight's accusations, Twilight attempts to warn Shining Armor, only to witness Cadance place a seemingly evil spell on him. Twilight accosts Cadance at the wedding rehearsal, causing her to break down in tears. Shining Armor, furious at Twilight, dismisses her from being his best-mare and bans her from the wedding. Twilight's friends and Princess Celestia, also angry at Twilight, abandon her to go check on Cadance. When Twilight tries to apologise, Cadance uses a magic spell that teleports her underground, leaving with a malicious grin.