I would almost 100% look In the fridge but might not take anything I just like looking at food. Even if you don't have cameras, you should at least say something to make them think they are being recorded. It doesn't always work but it will seed his thought process. Also, just ask say that if they want something from the fridge let you know and maybe they could help you out getting anything replaced? You also have to remind them it is a favor and that you will remember this and expect an equal favor sometime. Most of my cousins would not come to my house tho, so you must be at least kinda nice