His son and his wife suddenly came to visit without any prior notice. Apparently, they happened to be in the area for work and had dropped by. The father was relieved to see that the couple seemed to be living a happy married life. However, this was short-lived. As soon as his son left the table and he was left alone with his wife, she suddenly said, "I have something to talk to you about." The couple's relationship was fine, but they just couldn't have children. "Please give me your sperm, father-in-law..."