No one in my family are welcome in my sewing room unless they have been invited, except the dog. They have learned that if they touch my scissors or cutter, that they don't want to pay the consequenses. If the scissors don't have red nail polish on the blade....don't even THINK of using the scissors.
When a pair of scissors is given over to them, it gets a blob of red nail polish so that they can identify the ones they are allowed to use.