I'm tempted to ask what our response will be when we are gambling and our kinds come to ask what we are doing. Do we lie to them or tell them the truth. At a certain age children become so inquisitive that they ask questions virtually in everything they see us do.
I believe there are certain restrictions to what a child should be seeing you do as a parent, where else you know that your child is very inquisitive and always wanting to learn, do not let him find out. In a case where your child ask what you are doing, you tell him the truth but if you do not want him to get involved tell him all about the risk and the bitter part of it that should scare him from gambling