A man and a woman were waiting at the hospital donation center...

A man and a woman were waiting at the hospital donation center.Man: "What are you doing here today?" Woman: "Oh, I'm here to donate some blood. They're going to giveme $5 for it." Man: "Hmm, that's interesting. I'm here to donate sperm, myself.But they pay me $25." The woman looked thoughtful for a moment and they chatted somemore before going their separate ways.Several months later, the same man and woman meet again in thedonation center.Man: "Oh, hi there! Here to donate blood again?" Woman: [shaking her head with mouth closed] "Unh unh."