No, don't like it a bit. But I understand why it might appeal in dom/sub situations.
I had a one-off where a guy did so to me without any warning or asking. There was no dom/sub/extra-slutty context before this moment, and I think, at the very least, that's a good bar to set.
Someone will counter that it ruins the "hotness" or "spontaneity," but mouth spitting doesn't work well, IMHO, as a surprise.