A sweet young girl walks into an elevator at Harrods, trailing a cloud of expensive perfume.
She brags to the elderly woman who was inside, Coco Chanel £900 per ounce.
The lift reaches the second floor where the old lady is about to get off. As she steps out of the elevator, she rips out a rumbling fart. Trailing a heavy cloud, she smiles sweetly and announces, broccoli, 49p a kilo.