One day Adam and Eve notice God standing before them, holding a bag.
"Hi, God. What's in the bag?" asked Eve.
"These are a couple of things that were left over from creation that I thought you two would be interested in." God rummages around in the bag a moment. "Okay who wants to be able to pee standing up?"
Adam immediately puts his hand up in the air, waving frantically. "Me! Me! Me! Oh, oh, PLEASE, God, let me have it! Just think of how much more work I could get done in the fields if I could pee standing up! And it would help so much when I'm out hunting! Oh, please, please, please let me have it!"
"Well, all right," says God. "Now, let's see what we have for you, Eve." God rummages about a bit more in the bag.
"Ah, right. Multiple orgasms."