Fluttershy taking care of her (not so) foal Pinkie Pie. Here, she is giving her a diaper change, putting on a new diaper while Pinkie sucks her hoof.

Apart of Pinkie Pie's randomness is that she likes showing her inner foal and when doing it, she likes having Fluttershy take care of her.

Background vector owned by bitterplaguerat on Deviantart here; https://www.deviantart.com/bitterpl.....Wall-346781450

Disclaimer: MLP belongs to Hasbro.