Transcription:
How To Confound A Centaur
Centaur: Hold it right there, you can’t just ride through my fields uncontested! I’ll lose my credibility if we don’t battle or something.
Me: That’s fair. How about we–
Centaur: And it can’t be a pun battle, I heard what you did to the sphinx.
Me: Darn. Okay, what if I beat you in a horse race?
Centaur: Ha! Alright, your funeral. Where’s the finish line?
Me: That tree over there. Where’s your horse?
Centaur: (gestures at horsey backside) Um…?
Me: You’re not a horse, this is a HORSE race. You have to race with an actual horse.
Centaur: You want me… a centaur… to RIDE a regular horse.
Me: That is, linguistically-speaking, what you agreed to.
Centaur: …
Me: …
Centaur: I hate you.
Me: That’s fair.
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And if the answer to that is yes…is it more or less gross than if the centaur borked a human?
Way less gross. Human and centaur are both intelligent, can communicate, and give consent, so it would be fine. With a horse (which has none of these things) the centaur would be committing bestiality.
Apply the Harkness test (self aware intelligence, physical maturity, and ability to communicate consent). Both humans and centaurs pass assuming the individual is a willing adult, horses fail twice due to being nonsapient and uncommunicative.