Rainbow Dash has been extremely protective of Fluttershy since fillyhood. Bullies got a piece of her mind, hurtful comments were squashed instantly, and any mean teasing got the one doing it in really big trouble.

Nopony thought much about it, and Fluttershy never complained and seemed happy about it. But when Dash takes her protectiveness too far, its time for somepony to ask the question: "Why are you so protective?"

The answer isn't entirely what was expected...