Supermarket

A young  man shopping in a supermarket noticed a little old lady following him around.  If he stopped, she stopped.  Everywhere he went, she seeming to be staring at him.
She was in front of him in the checkout line and turned to him and said, "I hope I haven't made you feel uncomfortable. It's just that you look so much  like my late son."
He  answered, "That's OK."
She then said, “I know it's silly, but if you'd call out ‘Good bye, Mum’ as I leave the shop, it  would make me feel so happy."
She then went through the checkout and as she was on her way out of the shop, the man called out, "Goodbye, Mum."
The little old lady waved and smiled back at him.
Pleased that he had brought a little sunshine into someone's day, he went to pay for his groceries.
"That comes to £121.85," said the cashier.
"Why so much?  I only bought five items."
The cashier  replied, "Yes, but your Mother said you'd be paying for her things, too."