Kristin Cavallari KristinonTheHills.jpg

E! Online is reporting the best news ever! Lauren Conrad's former rival Kristin Cavallari - from MTV's reality show Laguna Beach - might be making a guest appearance on The Hills... and therefore reuniting with nemesis Lauren. And according to the same inside source, L.C. is not happy about it!

OMG! Lauren and Heidi and Kristin on the same show? It's not even my birthday today! (But it is Brad's... maybe he was hoping for this, too?)

So, are you Team Lauren or Team Kristin?!