You refuse! (And incur her wrath?)

It should be irresistible, filtering the flatulence of the most revered being in all of Equestria, but you just can't find it within yourself to accept. It's a number of things, really--every other time you've been bought by a mare or stallion there was always Cherry Jubilee to fall back on if things got too difficult. And, taking another cautious sniff of the putrid stench she's flooded this carriage with, you're not sure you’re up to the task.

Sure, you've dealt with ponies before whose farts were so foul you lost your sense of smell for a week after leaving their service, but there's something patently different about Celestia's brew. That tang of spoiled milk... that spicy, smoky afterkick, the way it makes your guts do cartwheels every time you breathe it in. And these aren't even direct from the source. You may have a talent for whiffing pony poots, but no amount of natural skill could ever prepare you for an alicorn.

Celestia can see the doubt in your eyes. Smell your fear (which is a miracle given how saturated the air is with her own stink). You push her away, but her wing tightens its grip and keeps you in place.

"I'm sorry, your majesty. I'm really flattered, but I-"

She waves a hoof. You fall silent immediately.

"It's a real shame, Fart Bitch. I offer you everything, and you spit in my face."

Wait, you didn't mean it like that!
"N-No, it's just-!"

"Silence!" Her voice is almost as threatening as her butt bombs. Before your very eyes Celestia's good mood turns sour. It's like watching a placid blue sky turn to grew stormclouds within just a few seconds. There's that scowl again, firmly on her face, only this time you can feel that it's completely sincere.

Celestia is not accustomed to ponies telling her ‘no’. In fact, she’s so unaccustomed to it that she takes even the most polite denial as an offense to the crown.

"So you want to disobey your princess, do you? Make a mockery of me? I asked you nicely, I was actually starting to take to you, but I can see plainly now that you have no respect for me or my desires."

There's a hoof on your head and Celestia violently slams it down against the seat. Before you can recover from the impact she raises her vast rear and smashes that down atop your head. Your world becomes darkness and moist warmth. You try to wriggle away but her weight is just too mighty.

"Just know when you're suffocating on my fumes and wishing for **** that this could have been so easy." With this damning words Celestia pushes all her strength into unleashing a gale of foulness onto your face, steaming your head like a cabbage.

BRRRRRRPT

The stink is thick and heavy, noxious and absolutely unbearable. But you're pressed right up against her plot now. There's no escape from it whatsoever, as it defiles your nostrils and throat with pure evil.

All you can taste and smell is mutant vegetables and putrid cream, layered with a cloyingly sweet kick and that same nostril-sizzling spice. There isn't a single particle of oxygen in this prison Celestia has condemned you to.

For the rest of the trip to the castle she says nothing, only feeds you frequent blasts that get you writhing in agony every time. Before her scent was almost tolerable, but now it brings nothing but pain.
After what feels like a lifetime of enduring her undiluted wretchedness, the chariot touches ground and Celestia departs. Guards hoist you out behind her, no doubt feeling lucky they're not in your place once they catch wind of what she's done to you.

"Escort her to the dungeons. I shall be with her again shortly, I need to inform my sister of our new royal fartrag."

With this, Celestia storms off and the guards drag you across the courtyard and down a narrow flight of steps. You don't bother fighting them, you don't even have the strength to do so. Everything went from roses to weeds so fast that your head's still spinning (though that may also be a side effect of inhale pure princess nukes).

They hurl you into a dark, damp room where the only light source is a tiny window fitted with iron bars. This must be the castle dungeons. You'd always hears rumors of them but never believed such places truly existed.

The door to your prison slams shut and you then hear the guards all laughing and arguing about who gets to use the shower in the barracks first as they disappear down the passageway--the only way in and out.

As you slump against the wall your nose is still aching with the aftershock of Celly's pure fumes. It's like she only just cut a fresh one in your presence, that's how long this stench takes to go away.

Your senses adjust to the dim room around you. Now you notice the floor is littered with all sorts of curious things: empty cans of beans and stew, half-eaten artichokes and heads of broccoli, onions that have been bitten into like apples. There’s a pair of stocks and what appears to be a rubber mask with a long hose snaking out the front of it. You’ve encountered enough of those in your time to know what it is. What kind of sick shit do they get up to in here? You probably don't want to know the answer to that, but have a horrible feeling you're going to find out soon enough.

There's also a very curious afterscent hanging in the air, almost like someone was just using this room for something not long before you got here. It's not Celestia's farts, you'd be able to identify those a mile away. This is something different, something distinctly more rotten. It must be the lingering presence of Luna's gas. If this is what it smells like in its vestigial state, you really, really do not want to experience it first-hoof.

You lay back against the wall and start to sob. Sooner or later that door is going to swing open and bring with it a fresh dose of hell. After about an hour of wallowing around in your own misery...