I'm not sure if you got my point...we would never have done it otherwise even if there's only one other people, we wouldn't want to disturb others at all (and that's why we hate this new J). but in our case we were the only two in the whole upper deck cabin and there's no 3rd person around at all (the 3 crew were all in the galley most of the time). and we were not really "shouting", but just talking a bit louder so that the other could hear (but which usually I would already consider to be loud enough to be disturbing people in the cabin).