English to French Other Slang Saying / expression

PHRASE:
For arguments sake let’s say I was a horse, even so it’d be hard to imagine how hard my first wife rode my ass. I’m a small man, and not necessarily of what you would call good health. But I took it from her for six long years.

CONTEXT:
It is part of a script with characters who are animals. The one speaking is an ORANGUTAN.

EXPLANATION:
The character is being funny… he is making a joke based on the literal and figurative meanings of “riding an ass”… To ride someone’s ass figuratively is to give them a really hard time. And he is saying it in the literal way, as if he were a horse (but a very small one, so he’s not sure how she could do so much riding).

Any suggestions / ideas? Perhaps something with a FR expression using 'cheval' or 'âne'?
(I admit I am feeling truly stuck!)

MERCI