Some newly married friends were visiting us when the topic of children came up. The bride said she wanted three children, while the young husband said two would be enough for him.
They discussed this discrepancy for a few minutes until the husband thought he'd put an end to things by saying boldly, "After our second child, I'll just have a vasectomy."

Without a moment's hesitation, the bride retorted, "Well, I hope you'll love the third one as if it's your own."