For me, it started out entirely a "bedroom" thing. That was because it grew slowly out of kinky sex (you know the progression: add handcuffs, add clothespins, add gags, add whips, etc...). The more the D/S part grew in importance, the more separate from the sex act it became.

Now I get the same kind of rush from all kinds of activities--and some of them (discreet hair pulling, verbal domination, etc) can be done surreptitiously in public. Often this is just a pre-cursor to "play" later on, like foreplay is to sex, but sometimes it is just what it is.

We do have very busy lives though, AND a child at home so nothing too serious will take place in "public" time.