The sound of trickling, splashing water filled the room as Twilight's horn made sure the door was sealed shut.
This was about the only time of day she had to herself and away from Spike, and a nice warm bath was something Twilight loved more than almost anything else.
The tub was progressively filling with steaming water; she dipped her hoof in to check that the temperature was just right, and it was.
Finally, and with a ample sigh of relief, she began to submerge herself into the porcelain trench.
Her hair fuzzed up before draping down in the growing humidity of the bath water, and very soon she found herself almost fully emerged -- save her upper body.
A small, ethereal sigh passed through her lips as Twilight felt every muscle in her body relax, although she was not in complete comfort.
Her stomach let out a deep gurgle, like reverberated low beats of a bass drum and she rested one hoof over its bloated surface.
A similar, sonorous rumble again came from deep inside her, and Twilight's stomach cramped uncomfortably; she shifted herself to one side just slightly, laying over onto one of her thighs, and her stomach roared at her again.
With a minute groan Twilight suddenly felt her buttocks ripple to let a flurry of bubbles come rushing up to the water's surface; producing an undulating drone and a moist bubbling as they broke the surface.
Suddenly Twilight gulped and her cheeks grew a reddish hue.
She realised that the sound of the bath running managed to mask the sound of the release, and she lay back in relief that Spike had not heard something so embarrassing.
The humid air around Twilight soon began to grow sour, and she realised a tangy scent of something vaguely vegetable-esque.
After taking a few more sniffs, she realised that what she was inhaling must be the musk of her own fart, and it smelled pretty good.
Nopony could hear her, and she did need to give herself relief anyway, so Twilight figured letting a little gas go couldn't possibly do any harm.
Folding both her legs up against her body, Twilight allowed the discomforting pocket of air to slip quickly and harshly from her anus, resulting in a little seethe of methane bubbles on the water's surface.
She giggled quietly as she was again surrounded by another pleasantly rank cloud of effluvia, sniffing it in secretly and wondering why the smell pleased her so.
It seemed to her that those crispy hay fries she'd eaten earlier that day hadn't settled well with her stomach, and so it was not long until she felt that familiar bloat near her butt.
Lifting one leg up and out of the water, and using a hoof to squeeze her cheeks together, Twilight let another hot flush of gas-containing globules rush up from under her with a sound much like that of a badly-played sousaphone, erupting into another pleasing gurgle as they burst on the threshold.
She sighed, looking down at the little mousse of bubbles left resting on the skin of the water before craning her head right to the spot and taking a whiff.
She was bombarded by the hot, spicy stench of digested and putrified foods, amplified by the humidity of the bath's water vapour, but felt no need to gag whatsoever.
The odour satisfied the alicorn in such a way she was not familiar with at all; this alien sensation in her nethers was both scary and pleasing, and she wasn't sure how to react other than to just blush a little to herself.
Twily pulled the plug, with intention to put it back in when the bath was near-drained; she wanted a constant running of the water so Spike couldn't hear her or her sordid actions.
Her belly really was quite discomforting, and Twilight was keen to flush out all of the gas as soon as possible.
For the next release, Twilight pressed her butt right against the base of the tub, both cheeks spread apart and her plothole pressed hard against the bottom of the bathtub.
Her stomach churned, and soon she felt another slither of swelling gas barge its way to her rear.
The resulting sound was nothing short of loud and croaky, the bubbles managing to force out past the limited space they'd been given with a boisterous, muffled groan.
As the bubbles began to surface and softly tickle her lower body, Twilight felt that same tinging around her marehood, giggling and blushing as it sustained.
One large bubble of miasma rested on the facet of the bathwater.
Twilight grinned and lowered her muzzle right to it, using it to pop the bubble and get a concentrated whiff straight into her nostrils.
That same sensation she felt surged strongly, and she couldn't help but let out a little yelp of pleasure, quickly covering her mouth in embarrassment.
The bathwater's level had reduced much now, now only up to about Twilight's thighs.
Before putting the plug back into the bath, she took this opportunity to see how her fart's dynamics might sound in this semi-submersion, leaning forwards onto her airbag of a belly and letting an exceptionally large barrage of gas exit, producing a wet, effervescent sound as the water lapped over her plothole, the fart being released half in the water and half out of it.
A louder moan escaped Twilight now, as she was again encompassed by a fresh dosage of the inspissated vapours which arose up around her in a haze, its scent slowly growing more malodorous.
Her marehood was positively throbbing now, and Twilight decided to rub it with her hoof.
She wasn't sure what this would accomplish, but when she felt that virgin feeling of satisfaction she let a long and vehement groan spill from her mouth.
Twily lay back again into the slowly filling tub, still rubbing at her clit and biting her lip to muffle the moaning.
She felt her gut was now substantially less painful; she decided to expel the final vestiges of gas left still inside her.
Still with one hoof stimulating her sex, she used the over to wipe over her belly in a circular stroke, grinning as it gurgled in response.
Within just a few seconds, another cluster of stink bubbles crowded the top of the water and all exploded into fireworks of odour.
Twilight sighed and then took in a deep sniff, feeling rather close to climax.
This feeling rose, and Twilight could no longer hold back her pants and gasps of consummate pleasure as one final crescendo filled the water's surface with a lively clamour of wet bubbles, and in that moment Twilight came hard into the bath, not able to suppress the orgasmic whine.
Once she'd overcame the wonderful, and new sensation of an orgasm, she lay even further down into the water with a deep sigh, stewing in her fart-scented soup as the water soon filled the bath and she turned the tap off.
