"Walking the dog"
This young girl about 7 year old had a dog which she took for a walk everyday after school. Well, one day her dog was in heat, so her father told her that she couldn't walk the dog for a week or so because it wasn't feeling well. His daughter became very upset and cried for most of the night.
The next day the father came up with a plan. He put some gasoline on the dogs rear end to hide the cover the smell from the male dogs.
Well when the girl got home she was happy to find that she could now walk her dog again.
About an hour later the girl returned without the dog.
The father asked, "what on earth has happened to the dog?"
The girl replies, "Well she ran out of gas a few blocks back and is being pushed home by another dog."