Cat gets ride

Yesterday morning I was riding the bus up Fillmore Street. Somewhere between Lombard & Union, everyone on the bus started laughing. I looked up from my book to see why. A man on the sidewalk was walking his dog. The dog had a cat standing on its back. A woman on the bus said to her companion, "I don't know what's funnier, that the dog tolerates it or that the cat tolerates it."