Adventures in dog sitting

I'm dog sitting for the next few days. He likes to steal things, and let you know about it.  I walked in and put my shoes for work down, and he immediately picked on up and walked out on to the sunporch with it. He doesn't keep the stuff, or fight giving it back, he just grabs stuff and walks away with it. A minute ago he walked into the room with a blue teddy bear. Pretty sure it's not his.  Silly dog.