Katy Perry and Nicole Sherzinger in the Battle of the Boobs!

We all love a celeb fash off, so we what's to say we won't love a celeb boob off?

Battle of the boobs: it's Nicole vs. Katy! Copyright: [rex]

Well, Nicole Sherzinger and Katy Perry both got the er, girls out over the weekend so it would be rude no to, eh?

Plus, it's Sunday there's not much on telly and we are bored.

Katy Perry looked absolutely fab in her plunging floral gown at a charitable 'do raising money for autism.

We are sure everyone was feeling much more generous after gorge Katy perked up proceedings.

However, when we managed to tear our eyes away from Katy's neckline, we were greeted with a rather pale complexion.

Bit of bronzer would hardly have gone amiss, eh?

Two ladies, four boobies.... did we really j! ust say that? Copyright: [rex]

Meanwhile, Nicole's cleave was in aid of a dinner at the Old Vic in London ahead of this weekend's X Factor live shows.

Nicole looked as stunning as ever in a curve boosting basque and structured blazer.

We want to know if she ever has made a fashion faux pas? She certainly hasn't here and just check her out at last night's X Factor!

But the question is: whose booby airing fashion did you rate the most: Katy or Nicole?