Seems God was just about done creating the universe, but he had two things left in his bag of creations, so he decided to split them between Adam and Eve. He told the couple that one of the things he had to give away was the ability to stand up while urinating. 

"It's a very handy thing" God told the couple, "and I was wondering if either one of you wanted that abilty."

Adam jumped up and blurted "Oh, give that to me! I'd love to be able to do that. It seems the sort of thing a man would do. Please give me that ability. It'd be so great. When I'm working in the garden or naming the animals, I could just stand there and let fly. It'd be sooo cool. I could write my name in the sand. Please, God, let it be me you give the gift to, let me stand to pee, oh please." 

Eve just smiled and said that if Adam really wanted that so bad that he should have it. It seemed to be the sort of thing that would make Adam really happy, and she didn't mind if Adam were the one to get this ability. Adam was happy, and proceeded to wash down the bark of the nearest tree, laughing with glee all the while.

"Fine", God said, looking back into his bag of leftovers. "What's left here?" "Oh, yes. Multiple orgasms."