Taylor tweeted about it!

taylorswift13
Surprise guest at Staples Center: @katyperry!! We sang Hot N Cold and jumped up and down a lot. Katy! LA! I will always love you! 5 minutes ago via web

here's a picture:



Justin Timberlake, Jessica Biel and Perez Hilton also watched her show

katy looks great.
and oh, i hate Perez

Perez

Btw Taylor and Katy look cute

Katy looks good. Perez has lost a lot of weight! Can't stand him though.