Unsurprised to see Rarity missing from this messing list.
I bet Twilight sleeps in her own mess more often than Fluttershy but isn’t listed here because she doesn’t enjoy it. She just craps herself while absorbed in a book, then keeps reading until she falls asleep without getting up to clean off.
@RMP116
(Rainbow Dash, wearing her skintight pants, and Rarity, wearing a light blue tank top and a skintight pair of purple shorts, begin farting repeatedly. At first they are short, loud, wet farts, but then their farts get longer. They come close, but Rarity’s longest fart is slightly longer than Rainbow’s. Rainbow is surprised but while she usually hates losing, she finds it amusing that a lady like Rarity could outfart her. Trying to top Rarity’s winning fart, Rainbow accidentally soils herself. Rarity poops her shorts after her next fart, and they both laugh about it)
@RMP116
Rainbow Dash and Rarity: I do!
(They look at each other and giggle.)
Rainbow Dash: Mind having a farting contest to prove that?
Rarity: It is on.
@Background Pony #4A5D
Rainbow Dash: Either or.
Pinkie Pie: Logs can be fun but diarrhea is so much more fun! It’s like sitting in chocolate frosting! Well, except I can’t eat it. But still, wiggling my tushie around in it is so much fun!
Applejack: Logs.
Sunset: Logs or hyperscat, but diarrhea isn’t so terrible.
Twilight: Diarrhea. I kinda like having really messy underwear.
Fluttershy: Me too.
Rarity: Logs are less messy, but diarrhea is easier to rinse out.
@BronyMan
Pinkie Pie: Of course! It’s always really funny!
Rainbow Dash: Same. More than funny if it’s Fluttershy.
Fluttershy: I like seeing Dashie poop her pants too.
Sunset: Yes, especially if it’s Twilight. However it smells…
Twilight: It is always fascinating to see anyone soil themselves without shame.
Applejack: Yep. Especially if it’s Rarity.
Rarity: There was a time I would have been disgusted, but now I rather enjoy it.
Twilight: Yes, you are correct.
(Rainbow Dash, wearing her skintight pants, and Rarity, wearing a light blue tank top and a skintight pair of purple shorts, begin farting repeatedly. At first they are short, loud, wet farts, but then their farts get longer. They come close, but Rarity’s longest fart is slightly longer than Rainbow’s. Rainbow is surprised but while she usually hates losing, she finds it amusing that a lady like Rarity could outfart her. Trying to top Rarity’s winning fart, Rainbow accidentally soils herself. Rarity poops her shorts after her next fart, and they both laugh about it)
Do it! I want to see who will win!
Rainbow Dash and Rarity: I do!
(They look at each other and giggle.)
Rainbow Dash: Mind having a farting contest to prove that?
Rarity: It is on.
Edited
Rainbow Dash: Either or.
Pinkie Pie: Logs can be fun but diarrhea is so much more fun! It’s like sitting in chocolate frosting! Well, except I can’t eat it. But still, wiggling my tushie around in it is so much fun!
Applejack: Logs.
Sunset: Logs or hyperscat, but diarrhea isn’t so terrible.
Twilight: Diarrhea. I kinda like having really messy underwear.
Fluttershy: Me too.
Rarity: Logs are less messy, but diarrhea is easier to rinse out.
Pinkie Pie: Of course! It’s always really funny!
Rainbow Dash: Same. More than funny if it’s Fluttershy.
Fluttershy: I like seeing Dashie poop her pants too.
Sunset: Yes, especially if it’s Twilight. However it smells…
Twilight: It is always fascinating to see anyone soil themselves without shame.
Applejack: Yep. Especially if it’s Rarity.
Rarity: There was a time I would have been disgusted, but now I rather enjoy it.
Edited