I make my son wear the mask even though he doesn't like it. I feel the germs go both ways - it's not only so he doesn't breath in other people's germs, but so he doesn't expose others to his germs. Not that he has ever cultured anything, but at the point we are at the CF clinic we don't know that yet. We are only in the waiting room for a minute or two while we sign in before they take us back to the rooms, but who knows who walked through there before us or who will walk through there after us. I just feel it's proper germ etiquette.