When my daughter was four years old she asked me if she could marry her dad. I provided a very logical explanation regarding the fact that daughters do not marry their dads.
However, the next night she asked me the same question. I once again explained how this wasn't how marriage worked.
When she continued asking me to marry him night after night, I realised reasoning with a four-year-old really wasn't working.
I was finally able to satisfy her by turning my "no" into a "yes" by telling her: "When you're 18 if you still want to marry him, he's all yours." She was delighted I had finally said yes!" - Priceless Parenting Anecdotes; first appeared in the Detroit Examiner.