Gordon Ramsay's 2nd favourite thing to say after "It's fucking raw"
"You fucking donkey" - Gordon Ramsay (the first class cunt)
Refers to the tendency of friends to nickname you after one humiliating incident and the nickname sticking.
Ryan: "What's up, rimster?"
Jake: "I regret telling you that. I let Sarah eat my ass one time. You break one plate, you're not plate breaker but you fuck one donkey!? and you're donkey fucker for the rest of your life."
The shortened version of "If a man has sex with a man, it doesn't make him gay. But you fuck one donkey, and everyone will call you donkey fucker until you die."
It means that some deeds are so horrifically memorable that you will be known for it, even if the act or event was a one time thing.
Bill: Hey guys! What are you cooking for Thanksgiving?
Simon: I don't want you in the kitchen, you might get a semi.
James: Haha, turkey fucker!
Bill: C'mon man, that was when I was 14. God....You fuck one donkey!