Sarah - you are definitely not mean and we do the same thing - DS is allowed to hold sometimes but definitley not open or try before paid for whether it be foodstuffs, toys or anything else for that matter and usually I contain things to the trolley otherwise you never know what state they will come out at the other end. He luckily has a fascination with "paying the lady" - to him that's the most important part of a trip to the shops.