Emotions really depend on double coincidence of wants.

After visiting the past in It's About Time, Twilight spends some quality time with Princess Celestia before returning to Ponyville. She then falls into a coma and wakes up where no living pony would ever wish to be, and things only get more complicated when Celestia gets an unexpected visit from herself. Featuring Twilight, Celestia, Luna, The Underworld, and some other alicorn etc.

After Nightmare Night, Luna invites Twilight to tea, and they start spending more time together. Princess Celestia teases Luna about it sometimes.

The six elements of Harmony took Twilight's birthday party to the Canterlot garden party in Sweet and Elite. But what happens after that? The party relocates again at the request of Princess Celestia, and Luna comes as well!

During their mission to defeat Discord and save Equestria, Rarity discovers her feelings for Twilight Sparkle. When Twilight finds out, she does some research to find a way to make the fashionista admit her emotions.