“Hey. Fluttershy.”
>”Um... yes, Anon?”
“Excuse me?”
>”Sorry... uh... yes... master? What can I help you with?”
“What do you think? It’s not like I have any other uses for you around here.”
>The Pegasus nods.
>”It is... um... number one, or number... two?”
>With a smirk you stand up and pull your dick from your pants.
>”Oh. Okay...”
“Don’t even think about spilling a drop this time.”
>She nods again and opens her mouth, her lower jaw trembling slightly.
>You aim as well as you can and wait for the stream to come out, it splashes her in the face initially but she quickly moves her head into position, letting it fill up her cheeks.
>She swallows and continues to take your piss in her mouth, wincing but knowing it’s all part of her job.
>The stream dies down.
>Being the attentive toilet she is, she approaches and licks the end of your cock with her tongue to catch any potentially stubborn drops that are left behind.
“You know what? It’s your lucky day. I gotta take a dump too.”
>”Oh... that’s okay.”
>You can tell this is the part she hates the most, but it’s also the part she’s become best at.
>The Pegasus lays down softly onto her back, pushing her mane out of her eyes and opening her mouth wide in anticipation.
>At one point in time it would have been a challenge to get Flutters to even consider doing this for you, but she’s learned it’s what she’s best at. 
>this is now her only purpose in life.
>just as casually as ever, you pull down your pants and squat over her, peering through your legs to make sure you’re in position.
>She’s trembling; no matter how many times a week she does this you don’t think she’ll ever get really used to it.
>Sometimes you find it funny to deliberately eat something spicy or horrible just to make her job a little bit harder.
>She deals with these instances well, though. It’s like she was made to be a toilet.
>The first thing to come is a fart which takes Fluttershy by surprise, but she obediently gives it a sniff. Not only does she dispose of solid waste but she stops you ever having to smell your own gaseous waste too.
>A few moments later you feel the shit spread open your asshole. It’s a pretty big load today.
>You always like to watch it plop down into her mouth.
>She judders, almost choking on it but starts doing what she does best and chewing it up.
“How is it?”
>”Mmh. V-Very nice, Anon.”
“So you want some more, then?”
>She nods.
>With a strain you push out another turd and once again watch as it disappears with a wet thud into her mouth.
>She chews and swallows. She’s past the point of gagging; she’s had to train herself not to.
>You’re almost done now, squeezing out one final log for her to eat.
>Now comes your favorite part.
“That’s it.”
>She understands and, finishing the mouthful of shit you’ve given her, pokes her tongue out.
>You feel it press against your asshole, carefully cleaning every inch of it, even inside.
>The sensation of a pony tongue licking your ass clean is one of the nicest you’ve ever experienced.
>Once you’re satisfied it’s clean enough, her job for now is done.
>Another meal disposed of.
>”Can I... go now, Anon, or do you still need me?”
“You can go. Not a bad job, Fluttershy.”
>You chuckle and ruffle her mane.
>Another session complete.
>Before long she’ll be begging to eat your shit.