I call him Monsieur when in a scene, or when the conversation turns that way; I sometimes call him Maitre, or refer to him as Maitre, when talking with others in the scene; or refer to him by him dom name (Léo), rather than his real name. Between us most of the time I call him by his name, and my affectionate non-subbing term for him is 'minou' - pussy cat . Cos he's a gweat big fierce lion, yes he is. We vous-vois eachother when in dom-sub mode, tu-toi eachother otherwise. I really enjoy the extra pith that gives to talk. We can say things to eachother in public in such a way that it is not at all eyebrow-raising, but there are lots of under-currents for us. I can call him Monsieur in public, too. Both those have to be in a slightly theatrical way, in order for it to pass, but it works.