But...RD is ALWAYS trying to hang out with Flutter Shy. And, I guess, the moral of Hurricane Flutter Shy is that everyone is important...but...even before that, there are moments where RD acts like FS's girlfriend. I mean, when FS first agrees to participate, RD rushes in and swoops her up and if it weren't a kids show, there would've been a closer hug and even a kiss. And when FS first decides she doesn't want to do it, RD kicks the ground like a girlfriend who's partner just ran off like FS did.
And besides...out of all the ponies....RD is definitely gay.
But, to be Honest, RD has an up-side-down rainbow for her mane and tail. Still though...she maybe a tomboy...but I think she's slightly more than that. But we really would never know the sexual orientations of the ponies 'cause the show's about equality, and so, even if RD was gay...the show would never admit it outright. It might imply it, but not in a really clear way. Because, let's face it. It really doesn't matter.