And thus, Luna came to be known as Moonbutt

Princess Celestia is, of course, voiced by Alumx in this scene.

@Background Pony #B0BA  
 
Indeed.

New headcanon, Princess Celestia “moves” pictures of her little sisters butt onto her computer to try and keep Princess Luna from being “corrupted” by the lewd standards of the internet.  
While Princess Celestia personally appoints her most trusted student to alter and enhance any photos of her butt found on the internet to enhance her reputation amongst her subjects.  
Lately between her and her student, if they find anyone online talking about mares and/or their butts. Princess Celestia gives strict instructions to Twilight to post the most impressive and enhanced photos of her butt for the ponies to appreciate, regardless if they actually want photos of Princess Celestia or not.

@Pyglik  
The internet’s not big enough for more than three of those.

Good, now search for your butt Celestia ;)

@Tetrominon  
That sounds about right.

@Napsack  

 
They call her Princess Tinyhiney for a reason.

I choose to believe that Tia thinks saving them to her own computer removes them from the internet.

If you’re a pony. Your bottom is on the internet.

Tag yourself I am Tia.

Good. Now show Twilight that she has the most porn of any single character in history.

@Background Pony #9F70  
Celestia is wise with her punishments. ^^

@Autumn_Shy  
So what I’m hearing is Nightmare Moon spent 1000 years shoved in her own ass.

“so many” should be replaced with “not enough”

Luna: “Those are pictures of the moon sister…”  
Celestia: “How scandalous of them all… Posting pictures of my lil’ sister’s butt!”