The little girls asks her mom if she can take her dog on a walk. "No, Fifi is in heat" The moms says. "What do you mean "in heat""? The little girls asks. Not wanting to get into this discussion the moms says "Just go ask your dad, I think he's in the garage.
Dad, can I take Fifi on a walk? Mom said no because Fifi is in heat. The dad pours some gas on a rag and scrubs the dogs rear. There, now you can take her, but only around the block and don't let her off the leash. "Okay!"
The little girl returned with a leash but no dog. "Where's the dog" asked dad. The girl replies "She'll be here in a minute, she ran out of gas and one of the other dogs is pushing her home."