Goodbye Mother!

Young Simon was walking around his local supermarket picking up a few items for his evening meal when he noticed an old lady was following him. He tried to ignore her but every direction he went she followed.

Eventually he went to the checkout, but the old lady managed to push in front of him and turned to speak to him.
“I beg your pardon,” she said, “I am very sorry if I have alarmed you by following you around, but you look just like my son who died recently.”

“I am very sorry to hear that,” replied Simon, “that must be very disconcerting for you. Is there anything I can do to help you?”

“Well there is one thing that would cheer me up a bit,” she said. “As I’m leaving, will you call out ‘Goodbye mother’ to me?”
“Of course,” answered Simon and as the old woman was leaving, he called out, “Goodbye mother!”

The girl on the till checked out his items and said “That will be $135.”

Simon was shocked. “How can my bill be £135?” he asked, “I’ve only bought a few things!”

The checkout girl replied, “Your mother said that you would pay for her!”