The I Kissed A Girl singer turned up with her beau Travis McCoy but later left his side to enjoy the show with the fellow fashion lovers.
Katy and Dita showed off their star style in pastel dresses by day and a more dramatic look by night.
Katy by day (left) & by night (right)
Meanwhile Lily cut a very different figure - ditching her trainers for killer heels and opting for a cute black and white number for the fashion bash.
