Image imported from derpibooru 
Original Description:
 
Ah, the adorible musings of those with little a care in the world. Warms the heart… as much as her crotch.
 
Third in a series of pic by Smudge Proof, beginning with Derpy in a locking diaper being denied the key so she could go potty. Second pic features the inevitable aftermath of said denial… and now the inevitable change. While in canon it didn’t take four years for her to go from dirty diapers to a changing mat (imagine the rash that would leave), exactly how long it took… isn’t up to me to decide ^^
 
Drawn by artist Smudge Proof. He’s personable, laid back, and works hard to get it just right for his customer. He draws a wide variety of stuff and is easy to talk to about commissions. Check his stuff out!