And me that I thought it was all a question of gradation in the touch with different variations of speed & depth, done under different rythmes to bring to best apotheosis possible.
Sloppiness is required of course, but "spitting", I do it if someone ask for it. It is more on the domination's side, like a "mépris" thing.
I often just let drop saliva very slowly, I think of this as to be very sexy, and the reaction I got from years proved to me I'm just right to think so ;-)