My answer to this. Reciprocity's a lovely thing...

In the beginning God created Man. And then he thought Man needed a companion, so he created Woman. But Man liked to sleep a lot and woman wanted to go out and shop or something, so God created the clitoris. Woman promptly forgot about it and kept complaining. So God created marriage so man would have to at least pretend to listen to woman until she finally shut her trap. Woman, however, never did stop talking, so God invented senility and woman finally started making sense. Then God got annoyed and created prostrate and breast cancer to kill them both off ironically. The End.