This joke now celebrating its 47th birthday
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!!!"