Thor, the Viking God of Thunder, and his pal Bob, were up in Valhalla,
when suddenly Thor said to Bob,
"Bob, it's been a long time now. I *really* need to have sex.."
Bob stood and pondered for a while, before replying,
"Go to Earth, oh Thor, and find thyself what they call a "prostitute", and give her a bloody good seeing to.."
And Thor did, and he saw that this was good..
The next day, he came back up to see Bob, and told him of the previous
night's events.
"Oh Bob," he said, grinning like a shagged out God, "It was wonderful. We had passionate sex 37 times.."
"37 times?!?!" exclaimed Bob. "You must go and apologise this
instant!"..
So Thor went back down to earth and found the aforementioned
prostitute, saying..
"I'm sorry about last night, but you see, I'm Thor.."
"You're Thor?!?!" Shouted the girl. "You're Thor?!?.. I can't even
pith!!!"
On edit: I copy and pasted this joke from
here. I had heard the same joke, or at least a varient on it, many years ago.