CLEARLY Dashie is straight. That is why there’s more art of her with AJ or Twilight than Soarin.

I feel like RD was originally intended to be straight but the writers figured they needed at least one gay or bi lead, and the rest is history.

Honestly though Dashie, if I were you I’d be happier with the mares. And chances are, she probably is.

Funny how Rainbow Dash has a RAINBOW MANE

I like the idea of RD being the only one who’s straight among the girls, it’s a hilarious take.

Honestly I could see Rainbow as Bisexual and Applejack as lesbian. But I still kinda ship them with Rarity over each other.  
Or Fluttershy, but the show has been teasing Fluttercord for so long that it’s the most “canon” out of the ambiguous ships, including StarBurst, AppleDash, YonaBar, etcetera.

@God_of_Awesome  
My own “conspiracy theory” as follows:
 
a) The show would probably not want to tease any ship unless they had some assurance that the staff was 100% on board with playing along with it. After all, any ship made even semi-canon is an invitation for voice actors to be harrassed by squealing fans about it until the end of time.  
b) Asheigh Ball had already playfully mentioned Appledash as a ‘favorite ship’ of hers.  
c) I don’t know what (if any) factors contributed to her supporting that particular ship, but I’m pretty sure a big factor would be that both characters are ‘hers’, so she doesn’t have to worry about annoying any co-worker by dragging their characters into her jokes. “Oh yeah! Rainbow Dash and Applejack all the way! They should totally make out in the next movie!”
 
Hypothesis based on next to no evidence, but… eh… tossing it out there all the same.

@Crimson “Valent” Azure  
Canon was very vague in that regard but it was strongly suggested, yes.
 
I don’t mind AJ being gay but making RD her special somepony felt like reaching for the low hanging fruit.

Jokes on you, Mr/Ms OP! Canon says the opposite!

well  
actually some people just think the opposite

@Crimson “Valent” Azure  
It was an available picture to contrast with the one below it. I looked up “Rainbow Dash Gets All The Mares” and looked for one where she seems less-than-enthused and then a similar but opposite picture.

I’m surprised this artist hasn’t made a remake with Zephyr and Quibble…
 
But I don’t believe RD is straight. She’s been really touchy feely with her friends more often than not and seems to have an obvious crush on both Applejack (tsundere) and Fluttershy. Besides some of these stallions are married, so why would they leave their wives just to be with Dashie. And if we’re talking married stallions where is Quibble?

Rainbow’s swag is so strong, it can steal Soarin’s attention away from the pie next to him.

@God_of_Awesome  
Mare has to satiate her heat somehow.

@Magatsu Orpheus  
My Twilight may qualify as bi, but she’s the type to require an emotional connection before desiring a physical one.
 
The end result is, so far, she’s gay because all her close friends so far are mares.
 
Also, she wants to bang all her friends.

@Background Pony #42C1
 
Well.
 
According to the Oxford Dictionary of English:
 
Bisexual  
/bīˈsekSH(o͞o)əl/ Adjective:(1)Sexually attracted to both men and women. (2)Having characteristics of both sexes. Noun: A person who is sexually attracted to both men and women.
 
Pansexual  
/panˈsɛkʃʊəl/ Adjective: Not limited in sexual choice with regard to biological sex, gender, or gender identity. Noun: A pansexual person.
 
In short, bisexuality is a sexuality where someone is attracted to both sexes, and pansexuality is a sexuality where the person in question has no preference for gender or gender identity.
 
But hey, don’t take my word for it.
 
It’s only the Oxford Dictionary of English.
 
In any case I think I’ll be going now.

@brujo_chilote  
ahmmhmm!  
Ah that is not correct…
 
But in all seriousness take it from someone who is pansexual: They’re not the same thing. I don’t wanna argue but just… they’re kinda not…

@Crimson “Valent” Azure
 
Hm. Guess there wasn’t enough room. RD also isn’t generally shipped with Fancy Pants. At least not to my knowledge.

@Background Pony #6F1B  
Nah, I’m just grumpy that it was (for a while) the most popular RD ship on derpibooru. I actually like the Wonderbolts compared to some characters. But I must ask, where is Thunderlane and Billy Dumbbell?

@Crimson “Valent” Azure
 
If you’d look for the source of the photo, it was clearly made before Zephyr and Quibble even existed. And Soarin isn’t a bad guy, he just makes bad decisions. He’s a bystander, a follower. He clearly cares for Rainbow just as much as he cares for Spitfire but he is too timid to stand up and break the Wonderbolts hazing traditions.

Also I just noticed something. TwiDash just passed Soarin/RD in the tags. Which means people are starting to wake up and smell the coffee and realize Soarin is a terrible mate for Dashie.
 
I want Rainbow with my male OC if she’s going to be straight and I don’t care if I have to blackmail DHX to get him in the show.
 
Joking aside, speaking of other stallions that might have an interest in Rainbow, this picture forgot Quibble and Zephyr Breeze. Zephyr’s annoying so I see why he was left out but what about Quibble Pants? And what about Spike?
 
I’d much rather she ended up with Quibble if she’s gonna end up with any stallion than Soarin or any of these others.
 
Nah, screw that! In my eyes she’s straight but only for my OC.
 
Also, I’m upset about it too, because I always saw him with Cheerilee but can we stop shipping Big Mac with any pony besides Sugar Belle? They’re canon now!

@Raritybro  
Bi = Pan

@Crimson “Valent” Azure
 
This photo came out before Thunderlane was confirmed as a Wonderbolt but I still agree.

@Background Pony #0ACF  
I can’t imagine them making any of the Mane Six lesbian and still keeping it child friendly. That’s not to say unless Rainbow ends up with Soarin in the end we can’t make our own headcanons. Who knows? It might just… “end” like TT did only without romance between Rainbow and a stallion.
 
Also where the hell is Thunderlane in Dashie’s male harem? Yeah, include two married stallions but no Thunderlane who is not only a Wonderbolt and a Pegasus but also from Ponyville.

@pinkieirrationalpi  
I want to tell you there’s no way she’s that dumb, but I don’t think I could actually say it with a straight face.

@Scrounge  
He tells her it is a self contantained cobbler, real fancy, from Prance, only beautiful awesome people eat these but I understand it might be too much for you. No, no, no need to force yourself to eat something so amazing.