The world of pop and beyond is divided into a before and after of the arrival ofBritney Spears.

Yes, but whose idea was it?

Lets do denim on denim!

Britney Spears and Justin Timberlake

Britney Spears and Justin Timberlake

Although Spearss comment was just a joke, eventually everyone decided to take it seriously.

But they both went all in, she writes.

Riff Raff and Katy Perry

Ugly or beautiful, tacky or not, it doesnt matter.

Britney Spears and Justin Timberlake

Britney Spears and Justin Timberlake

This story was originally published inVanity FairItaly.

Riff Raff and Katy Perry

Riff Raff and Katy Perry