“We would like to point out that living full-time in role is not the “gold standard” of BDSM. We see far too many players who feel that is they’re not “24/7,” they’re somehow wrong, or not “real” dominants. If this doesn’t sound like the way you want to live, if BDSM is a more comfortable fit in your life when you keep it in scene and drop roles the rest of the time, don’t let anybody tell you that you’re inferior. However, if full-time BDSM does feel like a good fit for you, we encourage you to try it”

Fluidity
“We’ve been friends with many people in full-time dominant/submissive relationships. Our observation is that when we spend time with such people as friends, we rarely see them behaving in ways much different than any other couple: the day-to-day demands of running a life remain the same, and must be addressed by someone or other. And almost nobody can be in full control of everything at every waking moment–or would like to be. While the dominants in novels (and sometimes chatrooms) express their dominance nonstop, in reality this approach doesn’t often work out very well.
“However, what we do see in successful D/S couples is a very strong ability to read each other’s signals and a very fluid approach to moving in and out of their dominant and submissive mindsets–so the couple who at one moment is discussing someone’s problems at work may at the next moment be in full dominant/submissive mode, with the dominance in complete control and the submissive completely pliable to hir will.
“What kinds of signals do these people give each other to make such extraordinary transitions possible? Some might be consciously chosen, like using a particular name (“boy” or “girl,” for example) or a particular behavior (a submissive kneeling, a dominant placing hir hand on the back of the submissive’s neck). Others are less conscious,more intuitive–a tone of voice, a shift in body language. Longtime D/S couples grow extremely skilled in reading such signals and responding to each other’s shifting needs and desires as the moment dictates.”
From The New Topping Book by Dossie Easton and Janet W. Hardy