A man and a woman are sitting in a waiting room and they start chatting. "So, whay are you here?" asks the man. "Oh, I'm here to donate blood. Getting 30 bucks for it. You?" The man replies, "Here to donate sperm. But they're giving me 100 bucks for it." The woman looks thoughtful for a moment and they continue chatting. A week later, the same man and woman meet again in the waiting room. "Oh! Here to donate blood again?" asks the man. The woman turns to him with a full mouth and shakes her head, "Hmm-mm."