Although Scout never really gets over her desire to eventually see Boo Radley in the flesh, her father makes it clear that his privacy is more important than her fantasy. When Atticus catches the kids play acting with the scissors in Chapter 4, he asks them if "this by any chance has anything to do with the Radleys?" When Jem lies and tells him no, Atticus responds, "I hope it doesn't." Scout wants to quit their game at this time because she knows Atticus has caught on. In Chapter 5, Atticus catches them with the fishing pole trying to deliver a message to Boo.
"Son," he said to Jem. "I'm going to tell you something and tell you one time: stop tormenting that man. That goes for the other two of you."
Later in the story, when Scout finally gets to meet him and greets him with a "Hey, Boo," Atticus reminds her that is name is actually
"Mr. Arthur, honey," said Atticus, gently correcting me.