A little girl asked her mum, "Mum, can I take the dog for a walk around the block ?"
Mum replies, "No, because she is in heat."
"What's that mean ?" asked the child.
"Go ask your father. I think he's in the garage."
The little girl goes to the garage and says, "Dad, may I take the dog for a walk around the block? I asked Mum, but she said the dog was in heat, and to come to you."
Dad said, "Bring her over here."
He took a rag, soaked it with petrol, and scrubbed the dog's backside with it and said, "Okay, you can go now, but keep her on the leash and only go one time around the block."
The little girl left, and returned a few minutes later with no dog on the leash.
Surprised, Dad asked, "Where's the dog ?"
The little girl said, "She ran out of petrol about halfway down the block, so another dog is pushing her home."