The joke isn't new - it can be found on the internet Urban Dictionary - but in Italy it has been given a political twist. It goes like this:

Two of Mr Berlusconi's political opponents are captured by an African tribe. They are asked whether they would prefer to die or undergo bunga bunga. The first one opts for bunga bunga, and is immediately subjected to a sexual assault by members of the tribe. The second one, who now grasps what "bunga bunga" means, says he would prefer to die. To which the chief of the tribe replies: "Okay, you will die - but before you will have bunga bunga."