A husband and wife had been trying for ages to have a child. When they had no luck, they decided to go to the doctor. The doctor told them that he could find nothing wrong with either of them. He then told them of an old wives tale that he knew. He told the wife to go home, swallow 2 ball bearings, get her hubby in the sack and have a really good romp. So home she went and did exactly what the doctor told her, and lo and behold she fell pregnant. They ended up having 2 kids, a daughter and a son. To cut a long story short, 16 years down the track the daughter comes in to mum quite worried and says "I just went to the toilet and had a pee and a ball bearing fell out." Mum told her not to worry as that happened to all 16 year olds. The daughter was quite satisfied. A few days later the son goes to his mum and says he has a problem. He's looking really upset but before he can say anything else, his mum cuts in and says "I know, you went to the toilet and a ball bearing fell out". "NO," said the son. "I was having a wank and I shot the cat!"