>You and Rarity burst through the door to Carousel Boutique in a fit of laughter.
>"O-hoh, darling, I don't think I've laughed that hard in ages!"
>You wipe a tear from your eye.
>"The way that mare had ice cream on her face for the entire evening and didn't even notice! Oh, when the waiter came over I thought I would burst!"
>This evening has gone by with much success so far.
>You knew that taking Rarity out on a date meant sparing no expenses, and if nothing else expenses were certainly not spared.
>The evening began with a meal at one of Canterlot's most expensive and opulent eateries.
>A restaurant so fancy you still can't pronounce its name correctly.
>Your table was graced by round after round of exquisite food, with you footing the bill of course.
>The feast started with a delectable mushroom pate and crudités, followed by a main course of lentil stew with a side of garlic-braised brussels sprouts and, rather unexpectedly, a cheese board for dessert paired with a fine Fillydelphian champagne.
>In order to burn off a few calories and "let things digest" as Rarity had put it, you both took the scenic route home through the royal gardens before hopping in the carriage which whisked you back to Ponyville.
>However, even with an evening full of fun and romanticism, things aren't quite over yet.
>After a few glasses of champagne the conversation had diverted into rather strange territory, and miraculously Rarity had managed to squeeze a secret request from you and then had agreed to fulfil it.
>You still aren't sure if she'll keep to her word or not.
>And now that Rarity has sobered up a bit she seems somewhat reluctant herself.
>Her smile fades.
>"So... dear, you're absolutely certain you still want me to-"
>Her lips form an 'f' but that's about as far as she can go before a bright cherry-colored blush erupts over her cheeks.
"I mean... only if you want to, I don't mind if we just-"
>"No. No."
>She presses a hoof to your mouth.
>"I'll do it. After all, you've been such a gentleman this evening, paying for our meal, taking me out to dinner. This is the least I can do."
>Yet again you find yourself awed by Rarity's generosity, but it is her element after all.
>She leads you through into the sitting room and directs you towards a wide chaise lounge.
>Butterflies gather in your belly as you approach and lay down, and by the sounds of it something is starting to stir in her own stomach too.
>She winces slightly, hastening herself to climb on top of you, her rear end pointed towards your face.
>Very few ponies would go to the effort of actually designing a custom dress for your dinner date, but Rarity insisted upon it.
>And the frock she "threw together in a couple of afternoons" is absolutely stunning.
>A plum purple ball gown with an elegant skirt billowing behind her like a large bell.
>As it happens, this dress is about to serve another function altogether that you never saw coming.
>Once Rarity is comfortable, the domed skirt lights up with magic and suddenly lifts above you, enclosing your head.
>Gossamer silk cascades around you, trapping you inside the many layers of thin, delicate fabric.
>"There. Now we shan't have to worry about anything too unpleasant escaping and souring the air in the room."
>You detect a hint of something sultry in Rarity's voice.
>If you didn't know any better, you'd swear she was actually getting into this idea.
>Another sound interrupts your thoughts, this time coming from Rarity's stomach.
>It roils and gurgles insistenly. You hear her groan in discomfort above you and shift around to get ready.
>As your eyes adjust to the dimness under her skirt, the sight of her ass fades into view.
>Your gaze follows her tail all the way down to the dock, then dares to venture below that to get an eyeful of Rarity's prized jewels.
>Her wrinkled asshole purses a few times as she strains to let an appetizer out for you.
>"Are you ready, darling? I think I feel something..."
>Not even waiting for your confirmation, Rarity's rump lifts and pops out a short, airy puff of flatulence.
>"Oh! Please excuse me..." She giggles.
>You're so surprised to hear Rarity fart that you don't expect the smell, which finds its way to your nose quite quickly.
>With the dress draped over your head like this, the thick fumes have nowhere to go but directly into your airways, as you take a curious whiff your eyes begin to water.
>For such a small toot, the scent is remarkably strong.
>An unusual mix of fetid odors mingle together into something that belies Rarity's image of perfect femininity.
>Taking a few more sniffs, you can pick out various influences from dinner.
>First and foremost is the sharp tang of garlic, which almost drowns out every over flavor note but not quite.
>Barrelling into your lungs alongside it is the stench of fermented cauliflower, and a buzz from the alcohol. 
>Even a pang of mould from the blue cheese she wolfed down by the slice.
>All in all, you can't get enough of it despite how potent it is.
>With every noseful of flatus settling in your lungs like a morning fog, you can tell you are inhaling something truly extravagant.
>Burning such a big hole in your wallet for dinner was absolutely worth it in more ways than one.
>You shift through the darkness to nuzzle up against Rarity's warm pucker, showing your appreciation.
>In response she titters like a filly, and grunts.
>A loud gust of gas roars out of her plot with the sound of wet, ripping cardboard.
>Rarity gasps in surprise and cuts it short after just two seconds, leaving you with a much fiercer wave of stink.
>"Oh, goodness..."
>She can't help but laugh at such a vulgar sound coming from her own body.
>"None of this ever leaves the room, understood?"
"Mhm..."
>You're a bit too busy drinking in her costly scent to give a proper response.
>Sweltering vapors build up in the impromptu gas chamber, turning the air around you ripe with her very unusual scent.
>Luckily for you, every breath is heaven.
>You never thought heaven would come in the form of stinky unicorn farts, but here you are.
>Starting to relax into the idea now, Rarity shoves back into you, pelting your face with a steamy hiss that lasts for at least eight seconds before tapering off.
>You open your mouth to taste as well as smell it, absolutely bathing in raw pony flatus and loving every second of it.
>Down below the waistline your cock stands firm in your pants.
>Rarity feels it pulsing against her and gets an idea.
>A cry of pleasured shock jumps from your throat as you feel the edge of her hoof stroking up and down your bulge.
>At the very same moment another gaseous gale pours over you, renewing the aroma that was already far from fleeting.
>"Just lie back, darling, and enjoy your treat. A lady knows how to pay back an act of generosity, after all."
>You were wrong before.
>THIS is heaven. 
>No, a step above heaven.
>You're absolutely giddy from either bliss, oxygen deprivation, or both.
>Instead of graceful sniffs, you now start huffing down the thick, veggie-scented air like it's a drug.
>Your nostrils are sizzling slightly with the pungency, but you don't even care anymore.
>You're about to cum to the smell of Rarity's own private dutch oven.
>Suddenly, the door to the room clicks open and sends Rarity into a panic, causing her back entrance to clamp shut like the aperture of a camera.
>But you're too far gone.
>Unable to hold back a moment longer, you moan and flood your pants with several rounds of hot cum.
>"Hey, Rarity? When you're done farting on Anon's face could you help me with my math homework?"
>It's Sweetie Belle.
>God damn Sweetie Belle.
>You thought Rarity said she was out tonight.
>The unicorn whose ass you're pressed into seems just as stunned as you are, and a few stammering attempts at words come from her.
>"Fine, I'll do it myself! And do you want to open a window, maybe? It really reeks in here."
>With that, Sweetie Belle gallops off up the stairs, leaving you and Rarity to try and pick up the pieces of this awkward turn of events.