A little girl asks her mom, "Mom, can I take the dog for a walk today?"
The mom replies, "No Sarah, you can't take her because she's in heat."
The girl asks, "What's that mean?"
"Go ask your father. I think he's in the garage."
The little girl finds her father in the garage and asks him, "Dad, can I take the dog for a walk today? Mom says I can't because she's in heat, and to come to you."
The father says, "Bring the dog over here." Then the father takes a rag and soaks it in gasoline, then scrubs the dog's backside with it to disguise the scent. "Ok you can take her now, but keep her on the leash and only go once around the block."
The girl returns a few minutes later with the leash but not the dog.
The father asks, "Where's Belle?"
"She ran out of gas halfway around the block, so another dog is pushing her home."
Don't know if this is original or not, it was posted at work and I thought you guys would like it. Written from memory, some minor details changed.