Rainbow Dash stared down from her cloud at Princess Twilight Sparkle. Her friend--her ex--talked and laughed with their other friends. But she couldn’t.
It isn’t that Twilight didn’t invite her or anything. She had personally shown up at Rainbow’s door to extend the invitation to her. All smiles, happy as can be. As if nothing happened between them.
Every ounce of willpower in Rainbow was used to not slam the door in her face.
Rainbow couldn’t go down there. She couldn’t laugh at Pinkie’s jokes, or rib Applejack about something. Not if it meant she had to smile while Twilight acted so normal. She just knew she would lose her cool and scream at her, ask her how she could just pretend to move on so quickly.
But Rainbow knew the truth. She had realized while Twilight stood on her doorstep, passing along the invitation. Frankly, she had known for a long time, but she hadn’t wanted to admit it to herself; couldn’t admit it to herself.
Their relationship had never been as important to Twilight as it had been to her.
While Rainbow had meltdowns, and flew back to Cloudsdale to hang out with old friends, and got shitfaced and made an absolute fool of herself, Twilight just kept living her life. Twilight had cared about her, sure, but she’d never really loved her, not fully. It made a sickening sort of sense that Twilight would move on so quickly, because what was there for her to move on from?
So Rainbow watched, and hoped that Twilight could someday find someone to love completely.
And when she couldn’t take watching anymore, she flew home and shut herself off to the world and screamed and screamed until her throat was raw, cursing Twilight, herself, everything and everyone. Eventually she ran out of the energy to stand and flopped over. And as Rainbow sobbed onto her cloud floor, some part of her wishing Twilight would walk in and wrap her wings around her again, she couldn't help but think:
It's such a drag.