Man: 'What are you doing here today?'
Woman: 'Oh, I'm here to donate some blood. They're going to give me Rs. 200 for it.'
Man: 'Hmm, that's interesting. I'm here to donate sperm, myself. But they pay me Rs. 1000.'
The woman looked thoughtful for a moment and they chatted some more before going their separate ways. Several months later, the same man and woman meet again in the same line.
Man: 'Hi there! Here to donate blood again?'
Woman: (shaking her head with mouth closed) 'Unh unh.'