"The Goblin" joke

Walking out her front door one morning, a woman notices a strange little man at the bottom of her garden.
"You're a goblin!" she exclaims. "I've caught you, so now you owe me three wishes."
"OK, you did catch me fair and square. What is your first wish?" asks the goblin.
The woman thinks for a moment and replies, "I would like a huge, beautiful mansion to live in."
"All right, you've got it. What is your second wish?" the goblin asks.
"For my second wish, I would like a shiny, new Rolls Royce," she says.
"Ok, you've got that too," the goblin says. "What about your third and final wish?"
"My last wish is to have a million dollars," she replies.
"All right, you've got it. However, in order to make all your wishes come true, you must have sex with me all night," the goblin explains.
"Well... if that's what it takes... " says the woman.
The following morning, the little man wakes the woman up. "Tell me, how old are you?" he asks.
"I'm 28," she replies.
"Ha!" says the goblin, "28 and you still believe in goblins?"