[undies]

Just when you thought you had seen everything, along comes "Pony Fetish".

Pony Fetish is based on...
Animal roleplay is a form of roleplay where at least one participant plays the part of a non-human animal. As with most forms of roleplay, its uses include play and psychodrama.
Animal roleplay may also be found in BDSM contexts, where an individual may take part in a dominant/submissive relationship by being treated as an animal. The activity is often referred to as petplay. However, not all types of animal roleplay within BDSM are petplay and not all petplay in BDSM involves roleplaying as an animal; some can be referred to as primal play and furry play.