It' rude to hide people's property from them.
Sam's sister Tammy asks him where her Gameboy is.
Sam wants to respond to Tammy's question.
Sam retrieves the Gameboy from his room and hands it to her.
Sam tells Tammy he doesn't know where the Gameboy is, while he hides it in his room, so he can play it.
Tammy is happy to have her Gameboy back.
Tammy is upset thinking that she has lost her Gameboy.