Young Man Notices A Lady Following Him

A young man noticed an elderly lady following him around while shopping in a supermarket. She stopped when he stopped and kept staring at him. Eventually, at the checkout, she approached him and said, “I hope I haven’t made you feel ill at ease; it’s just that you look so much like my late son.”The man replied, “That’s okay.”
She then made an unusual request: “I know it’s silly, but if you’d call out, ‘Goodbye, Mom’ as I leave the store, it would make me so happy.”
Obligingly, as she left, the man called out, “Goodbye Mom!” She waved and smiled back.
Feeling pleased for brightening her day, the man proceeded to pay for his groceries. The clerk said, “That comes to $121.85.”
Surprised, the man exclaimed, “How come so much! I only bought 5 items.”
The clerk replied, “Yeah, but your mother said you’d be paying for her things too.”