Dad Pranks Son With "Find the Money in Cups" Trick

This dad had an ingenious idea to prank his son. He laid out three cups on a table, put money on one them and shuffled it on the table asking his son to guess which cup has the money. If he guessed right, the money was his. However, earlier when his son was not present, he had already hidden larger money bills in the other two cups. His son guessed right but was aghast when his dad lifted the other two cups.