Katy Perry 'Last Friday Night (TGIF)' Video: Rebecca Black In New Music Video (WATCH)

We finally know just what Rebecca Black did on Friday night. Turns out it was crazier than any of us expected.

The teen "star," whose first music video, "Friday," has gone wildly viral in a cruel worldwide gangup, co-stars in the new video Katy Perry's similarly titled song, "Last Friday Night (TGIF)."

Playing the host of an insane, 1980's-set party, the delicious irony is that Black works to get glam up an outrageously geeky Perry, who appears as her oft-teased Kathy Beth Terry character.

In what looks like an extreme camp version of an 80s movie, Terry goes from sudoku-doing dork to teased hair-sex symbol. Just like that!