"Mom, may I take the dog for a walk around the block?" a little girl asked. "No, I dont think so. Fifi is in heat," replied the mother. "What does that mean?" asked the child. Embarrassed and not wanting to get into a biological discussion with her young daughter, the Mother said, "Oh, just go ask your father. I think he is in the garage."
The little girl goes to the garage and says, "Dad, may I take Fifi for a walk around the block? I asked Mom, but she said that Fifi was in heat, and that I had to come talk to you." Not wanting to have the biological discussion either, the father said, "Bring Fifi over here." He took a rag, soaked it with gasoline, and scrubbed the dogs rear end with it. "Okay, now you can go for a walk but keep Fifi on the leash and you can only go around the block once."
The little girl left, and returned a few minutes later with NO DOG on the leash. "Where is Fifi?" her father asked. "She should be here in a minute," advised the daughter. "She ran out of gas about halfway down the block and another dog is pushing her home."