Oh, I can see that the joke was made in Italian originallyI can't help it either and I hope you like it: there is a joke that has been going around in Italy since the European soccer championship. An Italian man goes to a pub in London and the bartender to avoid mockery immediately tells him, "We don't talk about soccer here!" The Italian thinks about it a bit and asks him, "Can we talk about sex?" And the bartender: "Yes, of course no problem!"
And the Italian: "Oh my God, what an fuckin asshole we've given you!
Although the slang "asshole" is coming effectively from "ass hole" (rectum, if you prefer the "clean" word), "a fucking asshole" would be more like saying a complete idiot. The "fucking" is an expletive meant to underline the fact of being an "asshole" (well, itselft the kind of word in USA they "beeped" in the past, and maybe even now), and/or as an extra insult to said "asshole", at maximum if one wants to make a double joke, it could be taking as meaning the "asshole" is actually fucking someone (even if not in the precise moment the phrase is said). I knew myself "fucking assholes" for whom both meanings of "fucking" applied :-D
I believe the closest translation to the Italian original would be "we really fucked you up you ass", "you really took it up your arse", and variations - though I bet we all understood the joke correctly anyway ;-)