"Johnny`s new bike" joke

A father came home from a long business trip to find
his son riding a new 21 speed mountain bike.
"Where did you get the money for the bike?
It must have cost $300," he asked.
"Easy, Dad," little Johnny replied.
"I earned it hiking."
"Come on Johnny," the father said.
"Tell me the truth."
"That is the truth!" Johnny replied.
"Every night you were gone, Mom`s boss, Mr. Reynolds,
would come over to see Mom. He`d give me a $20 bill
and tell me to take a hike!"