(Written under the username DashingMane)
Apple Bloom takes an impromptu bath after a hard days work. She enjoys it until she realises she is alone and there is no one to look after her. Given time to think, she discovers some things.

Inspired by cover art though there are differences for narrative purposes.
NOTES: Haydust is a real thing.
The top of a ponies foreleg is called a forearm, which means that ponies can be said to have armpits. Websearch it if you want to verify it I will brook no argument on the matter.