Yep, I have a sneaky yorkie! I always have to do spot checks on him to make sure he's chewing on his stuff and not something he found somewhere.
One time he was in my son's room playing with him, and he came downstairs with a ball that belongs to my son's cat. He layed on the floor chewing on it, and when my son would come downstairs, he would hurry up and lay on top of it to hide that he had it.
Funny thing was that my son knew and didn't care if he played with it lol