“After my child is born, I can physically nurse her for months and even years if I so choose. There is no way a man can feed a baby with a bottle and begin to experience the same deep fulfillment and satisfaction women feel when they successfully nurse their child.
“The experiences of childbearing and nursing are affirmations of female sexuality. Women were made to nurture life. It is an expression of our inherent femaleness, even if we never have a biological child. We are nurturers by God’s design.
By contrast, a man’s sexuality, his manhood, is primarily expressed through sexual intercourse.”
Here’s the link to her entire article: http://mentorguide.familylife.com/2011/07/why-sex-is-so-important-to-your-husband/