Yes, totally agree! In life we're very rarely told everything up front, it all comes to us in a series of revelations, little moments where we make connections between one thing and another, and when writers use this in a story, like Kitty does here, I find it so much more powerful as a result - as powerful as real life, which means that I can be dragged in and lost in the story, which is what I want from my reading!

So if we'd actually been watching B/D at this moment (*sighs*) we wouldn't have known the background to it unless/until we heard one of those telling moments - something said, a particular kind of touch or look. And our curiosity in watching in the first place would have come from wanting to know what was going on - not just what they were doing, but why. Otherwise, why not leave? Why watch/read anything?

Once we know what we think is the "full story" our attention wavers, we might actually walk away from something/turn over the channel - it's the same in fic. If there'd been any sort of explanation up front about what was going on, it would have taken away immeasurably from the story - because what would be the point of continuing to watch? That's when it would have become PWP - if we were watching without wondering about anything! (Whee - there's that little moment again! *g*)