Here is the original version of the joke, which most people have probably heard. (It's the original inspiration for the "Death By Snu-Snu" episode of Futurama, actually titled "Amazon Women In the Mood.") Here goes.
Two explorers are captured by a tribe of natives. The tribal leaders says to them, “You have trespassed on our sacred lands. There are but two penalties in our society, and you may choose which to suffer. One is a multi-day corporate management seminar. The other is death by unga-bunga.”
Explorers 1 and 2 look at each other.
Explorer 1: Uh, yeah, we’ll take the death by unga-bunga.
Explorer 2: Yeah. It’s, like, not even close.
Explorer 1: I don’t even actually know what unga-bunga is, but I already know I’d rather have that then the other thing. (Explorer 2 whispers something into Explorer 1’s ear.) Oh, yeah, that’s way better than the other thing.
Explorer 2: Yeah, the other thing is like being unga-bungad for eight straight hours a day, but without the sweet release of death.
Explorer 1: Look, there will probably be other explorers stumbling though here. If you see more guys who look like us, just go ahead and unga-bunga them on sight.
Explorer 2: Yeah, really. If they *do* pick the other thing, it’s because they don’t know what they’re getting into.
Perhaps silly posts like this one will ruin my credibility when I attempt a more serious post in the future. It's worth it.