Tonight's episode of Gossip Girl continued rolling out the cameos that have come to define the show's fourth season. Last week gave Tim Gunn. This week? A chocolate-covered Rachel Zoe and Robyn.

The fun starts at Blair's birthday party. It legitimizes itself with the presence of Bravo reality stars!

Next, Swedish pop sensation Robyn shows up with a tape of Blair drunkenly singing karaoke. The party takes a turn for the chaotic as Blair tries to stop the embarrassment.

Later, Robyn's music accompanies one of the year's most intense and expected reunions as Blair and Chuck meet in the dark for some hateful loving.

What does this mean for Chuck and Blair? How will they balance their hate with their undeniable sexual chemistry? How many more karaoke tapes of Blair does Robyn have?