In fact I expect even Flutters and Dash would have initially disliked each other. I can see Rainbow being a bit of a bully and being really pissed off at how weak and fearful Fluttershy was.
Kind of a Vriska/Tavros relationship.
Fluttershy <> Rainbow Dash.
@Meta: *shrug* Still, you would think their tensions would be more obvious then they were.
That's a good point, actually.
It really makes me wonder why the "Fluttershy and Rainbow Dash are old friends" fanon is so common.
Filly Rainbow Dash raced to defend filly Fluttershy's honor.
I just remembered. In "Griffon the Brush Off", Pinkie was acquainted enough with Fluttershy to know that pranking her was going too far. Yet Rainbow Dash was apparently okay with pranking Fluttershy, and had to be restrained by Pinkie. Hmm.

RD and FS had been friends (or maybe just "us against the world" acquaintances) in flight school, but they lost contact with each other not long after gaining their cutie marks, and only reconnected shortly before Twilight came to Ponyville.
edited 30th Jul '12 9:47:37 PM by MetaFour