On reading back through this thread, I see that my previous posting was unfair to my ex-sub.

She had a fantasy that she wanted to play out over a long period of time, she (and I ) were new to on-line scening, and you have to call your partner SOMETHING. If humiliation is part of your scene (and it was a big part of hers), then use of "pet" names (double entendre intentional) can be a scene setter, to put you in the mood or in the mindset. And if it helped her mindset to call me "My Sir", I have no business knocking it.

I suppose you could think of cliches as magical formulae -- they get repeated because they bring results. They MIGHT be the lazy man's way out, but they also form a common ground of experience. Sort of a reassurance that we're all on the same page.

Hmm. This thread has turned out to be quite thought-provoking.