What does Jem reveal to Scout about what happened to his pants?

Jem, Dill, and Scout are curious about Boo Radley. In chapter 6, they decide to sneak onto the Radley property and look in the window to see if they can get a glimpse of Boo. While they are near the house, the children see Mr. Radley's shadow, and they see that he is carrying a shotgun. As they are running away, Jem's pants get caught in the wire of the fence and he has to leave them behind.
The neighbors are gathered outside the Radley front gate as a result of hearing the shotgun. In an effort to avoid being seen as suspicious, Jem, Scout, and Dill join the neighbors. During the conversation, Miss Stephanie notices that Jem is missing his pants. Dill explains that he won Jem's pants in a game of strip poker.
That night, Jem makes plans to get his pants back. Scout fears for Jem's safety, but he returns safely with the pants. In chapter 7, Jem finally discusses his pants with Scout. He explains that his pants were in a tangle when he left them. However, when he went back for them, they were, "folded across the fence . . . like they were expectin' me." They had also been mended but not neatly. Jem then says, "Like somebody was readin' my mind . . . like somebody could tell what I was gonna do."