Good news and bad news
One day God was talking to Adam. 'I've got two pieces of good news for you and one piece of bad news.' he said. 'First, the good news - I've given you a brain. With this you will be able to learn many new and interesting things.. The second bit of good news is that I've given you a willy.' God continued. 'With this you'll be able to procreate, and give yourself and your wife a great deal of pleasure.'
'Thank you very much.' Adam replied 'Now what's the bad news?'
God sighed ' You can't use them both at once.' he said.