This YCH was firstly posted on DeviantArt and all three spots have been filled in one day... which is a surprise.

The characters, from left to right.
Mythic Majestic (genderbent to Stallion) - bigonionbean (on DeviantArt)
Khaki Cap (genderbent to mare) - khaki-cap (DeviantArt, Derpibooru & Furaffinity)
Flare (octopony) - blazep0ny (DeviantArt & Twitter)

I must thank to Bigonionbean for giving this picture such a great story.

"Whilst still under the affect of his nephew's accidental Genderswapping spell, poor little Khaki sought to collect her thoughts and mixed emotions in a place of solitude and tranquility, seeing the park as a place to do such. Little did she know that she would be the victim of a prank organized by a surprise twist of mischief by the usually shy, timid, and reserved Princess Mythic Majestic (now technically prince because of him being a stallion) alongside her spa friend octopony. Together the two planned to sandwich the stallion turned mare and take her by surprise..."

"What was meant to be a prank quickly turned into a ravenous love hugging session with a lust driven, booty hugging, emotionally hijacked and especially zeeb attracted Khaki turned mare now hungry to hug her some of that alicorn zeeb royalty butt. Served alongside with another mare victim in octopony being caught in Khaki's gravitational field of love and lust."

By the way, Derpibooru and Furaffinity ones are still open.
If somebody is interested in filling a spot, go here and comment. I accept OC and cannon. https://www.furaffinity.net/view/37453645/

Let's fill more of that butt sandwich love-lust. :3