WARNINGS! Rule 63. Diaper. Wetting. Sissy. Please don't complain or comment on how much its not your thing if I've given you this warning, this story isn't written for you.
Written in half an hour for a picture by Steel. The cover image is part of it cropped. Full picture in source.

Rainbow Blitz gets a very special delivery, and takes some time to stop being a stud and enjoy the chance to not be a strong, independent stallion.