One day Rainbow decided that she wanted to visit Fluttershy.
She really wanted to see her and talk, but the first Rainbow needs it to deal with Discord.
Old memories had been brought up.
Several hours later and about a dozen drinks later Rainbow finally managed to ditch Discord.
Rainbow decided to tease Fluttershy, "Hey Fluttershy, so did you manage to become a tree or not?"
It didn't go so well, not at all.