That is an interesting game to play with your daughters. Alittle social observation? Who came up with the idea and for what reason. Reminds me of a habit I have recently broken myself of. I never deny my wife anything that she asks for but just as a note of sarcasm instead of constantly saying 'yes' I would always say 'no' till one day I realized that this constantly being told no may be irritating, through this breaking process I realized how often I said no away from home as well, say work for example. I have never had issues in reguards to complaints on this sarcastic 'tic' but I guess I am glad to have broken it. Sorry to have gone off on that but like I said, you reminded me... It is odd how often we tell those close to us 'no'
Cool experiment/game though!