Drawn by Zombineko over on Furaffinity! Thanks very much!
For those confused about the comic, Swift Brush is a colt who is incontinent from birth, so he constantly has to wear diapers. He has a very big crush on Sweetie Belle, who accepts him, as in my world of OCs, she's a constant bedwetter, so she has to wear diapers every once in a while. So, that's why she's so easily able to use diapers around him, and that's why they're fine with changing each others diapers.
For those who can't read the text:
Panel 5: Sweetie Belle: "unf Why can't there be an outhouse somewhere near here? It'd be easier if I could teleport home, but neither of us know that spell yet!"
Panel 6: Swift Brush: "Sweetie Belle… I… I might be able to help you…" Sweetie Belle: "H-how?! Did you find an outhouse somewhere?"
Panel 7: Swift Brush: "If you like… I can give you my diaper to poop in… so you don't have to hold it anymore."
Panel 8: Sweetie Belle: "What?! Really?! B-but Swift! I can’t do that! I’m flattered, but you need that diaper more than I do! Unlike me, you CAN’T hold in your accidents!" Swift Brush: "But from the look of things, you can’t really hold it in either right now. At least if I have an accident, I have an excuse why I did. It’d be a lot more embarrassing for you. Besides, I wet myself back at the restaurant, so I should be good until we get back home."