More fat cyan pony delivered by Writefriend.  This one isn't too popular because of the lack of poneseks.
 
>Rainbow smiles "Then what are we waiting for? I'm pretty starved!"
>She starts walking to Sugarcube corner, and you follow.
>She can't be that starved, surely, that burger seemed pretty large...
>Rainbow hasn't gotten anywhere near as big as Fluttershy has, but you can tell she's a little softer around the edges
>You decide not to bring it up just now
>The two of you arrive at Sugarcube corner
>Holy shit food everywhere
>Not just the usual sugary stuff, either, burgers like the one you caught your Rainbro with earlier too
>You're not sure if introducing ponyville to some of your homeworld's delicacies was such a great idea sometimes, but looking at the effect this stuff is having on some ponies you don't mind at all
>You walk up to the counter with Rainbow and Pinkie bounces up as usual
>Huh, her bounces sounded a bit louder that time
>"Hey Dashie! Hey Anon!"
"Hey Pinkie. Love what you're doing to this place."
>"Hehe, yeah, when you showed us all those foods we got a LOAD more customers in, business is BOOMING! So I have to work here a lot more to serve everyone..."
"Heh, from what I can see, more repeat customers, too..."
>Rainbow awkwardly laughs, taking a quick glance at her small pudge, although at this point you were talking more about Fluttershy.
 
>Pinkie lifts herself a bit higher over the counter using her front hooves "So what can I get you two today?"
>DAMN, Pinkie's stomach seems to be sagging significantly now, bounce mystery solved
"We came here for some icecream, it's pretty hot out today, so can I just get a cone of strawberry?"
>Pinkie dashes off at her usual speed and brings back a cone for you
>You smile and take it
>"Er, I'm a bit more hungry, actually, Pinkie... You still do that Icecream tower supreme?"
>"Sure do!" Pinkie puts her hoof below the counter and pulls up a superb pile of Icecream
>A medium-sized bowl filled with a couple of scoops of vanilla and strawberry each
>...With a few scoops of mint choc. chip on top of that...
>With a few scoops of more vanilla on top of that...
>...With a large but single scoop of chocolate on that, with a cherry sitting upon the top
>Chocolate sauce drizzling down the whole thing
"Hey, isn't that thing meant for sharing, Rainbro?"
>Rainbow looks at you and smirks. "Is that a challenge?"
>You raise a smile.
"Ok then. If you can finish that whole thing in one sitting without being sick, I'll pay for both of us. You bail, you pay."
>Rainbow chuckles "It's a deal."
>You spit on your hand, she spits on her hoof, and you make the hand/hoofshake
"Pinkie, would you mind if we paid afterwards?"
>"Okie dokie lokie! Good luck Dashie! Enjoy your icecream Anon!"
>You both sit down at a table after you help carry Rainbow's icecream tower to stop it from toppling
 
>Rainbow Dash shows her usual enthusiasm in competition as she starts tearing away at this imposing feat of frosted treat
>You watch her eat as you take far more civilized licks at your single-scoop cone
>Well damn, she may not be as big as Fluttershy but she seems to have the same appetite
>No boner, not cool, don't even think about it. This is your best friend, not your stalker
>You wonder why the hell Rainbow would do this, seeing as last time you saw her she was still aspiring to be one of the best athletes in Equestria
>You look around. This place definitely has pulled in a lot of ponies, some you recognise as having put on a couple of pounds from when you first arrived here
>...It's probably just a coincidence, just the shift to this new food you brought, no way they could have...
>"Done!"
>You snap back to it, seeing your Rainbro's lips covered in ice-cream that just missed the gullet and an empty bowl
>No messes, either
"...Wow. Well, I'll admit defeat, there, I never thought you could do that."
>Rainbow gives a look of pride in response. "You know I'm always in to win!"
 
>You sigh, fish some bits out of your pocket, and get up from the table, finishing off the last few bites of the cone itself
>Rainbow lifts herself up, and you can't help but take a quick gawk at the bulge in her stomach from having to contain that much cream and chocolate
>"Something the matter, Anon?"
>You remove your supposedly stealthy gaze and turn back to walk towards the counter
"Er, nothing."
>Rainbow follows you, her belly losing it's usual firmness and beginning to move as she walks
"Here, Pinkie. Rainbow won."
>You somewhat begrudgingly pass the bits over to Pinkie, as she counts them into the till
>"Aww, it's okay, Anon, I'm sure you'll get her back sometime!"
>Maybe you don't need to...
>You leave Sugarcube corner with Dash, her being in a usual bragging state after a victory
>"I told you I could eat that whole thing, Anon! you should have seen the look on your face!"
>You turn towards Dash, deciding to bring this in via a joking matter
"Well, you should see the look of your stomach!"
>You give her somewhat bloated belly a poke
>...Wow, that felt... Pretty darn good.
>Rainbow blushes a little and awkwardly laughs again, and you bring your hand back
"...I'm gonna have to say, Dash, how DID you suddenly get this little pudge? I was sure you were training hard for the wonderbolts..."
>Rainbow's blush stays. "Er, oh, it's just a bit of puppy fat. I can lose that no problem, right?"
"Sure, you can."
>You spend the afternoon hanging around town
 
>In the evening, you go back to your place to watch a movie with the Rainbro
>She passes by the table, sneaks the last donut left from last night by Fluttershy and notices the broken chair
>"What happened there, Anon?"
"Oh... I just stood on it awkwardly."
>Made-up explanation doesn't seem legit enough
>Rainbow shrugs and sits down on the couch anyway to watch the movie
>You bring down some popcorn from your cupboard for you two to snack on
>Rainbow finished the donut once more under the impression you didn't see her with it
>The satisfied gurgles her growing stomach had given off were a giveaway
>You sit and watch Army of Darkness with Rainbro
>By the end of the movie, Dash leaves, admitting to be rather tired
>You see her out, noticing it takes her some effort to take off with the extra turbulence, then lie back down in bed
>Damn, this bed sucks now you've slept on Buttershy
>As you are fall asleep, you realise how much you were poking Dash during the movie, and yet she didn't seem to mind at all...
 
END