Because of my family background, I hear "arse" used fairly regularly as a less vulgar (almost as mild as "heck") anatomical reference. I rarely hear it used outside of my family (or BBC America), but I've never known anybody to be unaware of the variant.In my experience, that is a donkey reference (I use "jackass" because my vocabulary is quite tame), but I don't know if that's a universal association.

Some people threaten to kick my donkey. I answer that it's as stubborn as a mule :p

Q: What do you get if your donkey eats both of my chicken's legs?


A: You get two feet of my ______ in your _____

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Octavio Paz, the great Mexican philosopher, essayist and poet, wrote an excellent essay on this topic: What is the worst thing you can call a man (or woman) in various cultures? And what does it say about the culture? Fascinating topic!
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