When our second child was on the way, my wife and I attended a pre-birth class aimed at couples who had already had at least one child. The instructor raised the issue of breaking the news to the older child. It went like this:
"Some parents," she said, "tell the older child, `We love you so much we decided to bring another child into this family.` But think about that. Ladies, what if your husband came home one day and said, `Honey, I love you so much I decided to bring home another wife.`"
One of the women spoke up immediately. "Does she cook?"