Dear ThFH,

If you use a language that has the polite second person pronoun, then DO use it. My Master is German, and I always refer to him as Sie not Du. In my opinion, it is a wonderful way to have a solid "hierarchy" for us even in pulic, since no one will turn heads if you use that, which can't really be said about Master/Mistress or the like. I/we use those (Mistress...) when we're alone or among friends who understand more about our lifestyle.

Anyway, I just wanted to let you know that having your sub formally address you works wonderfully for me, and I always feel "more submissive" when I say that, because its a constant reminder of my role in the relationship (not that I really need it, but it works wonders).