Regularly go out for dinner with friend and their children (7, 9 yo) along with mine. Friend's children enjoy making "potions" with leftover food, coke, salt/pepper/sauces, whatever is available on table in discarded bowls, making a horrendous mess for the waiting staff. I think this is very disrespectful to the restaurant and tell them off and tell my DC not to get involved, however, it is awkward as their mother doesn't seem to mind and I don't like telling other children off. But I can't help myself!