Show business is full of vacant teens -- pretty and hollow and shaped by cynical grown-ups. Miley Cyrus and Justin Bieber, however, are not among them.

So it was surprising to see the sketch in tonight's "Saturday Night Live." It was another round of "The Miley Cyrus" show, repeating the false assumption that Cyrus is a no-talent ditz. And guesting was a clueless Bieber (played by the real Miley Cyrus, this week's host).

For a while, I thought this was going to be a backward "Saturday Night Live": The sketches were funnier than "Weekend Update."

Then things returned to normal:

1) Seth Meyer closed "Update" with a classic joke: The first Starbucks-at-sea has just opened on a cruise ship, he said. "And somehow, there's already a homeless guy in the bathroom."