First things first; there is of course a reason as to why Kristen Bell, Mila Kunis and Kathryn Hahn were swinging out of each other on the Billboard Music Awards red carpet last night - they're in a film together called Bad Moms. We're assuming it's about inept mothers and it's out later this summer (July 29th stateside to be exact...)

Now to the more important question of what they wore on the red carpet... Bell went with the current black flared jumpsuit craze courtesy of Jonathan Simkhai; Hahn wore a very spangly Altuzarra top and skirt combo; while Mila Kunis opted for a Zuhair Murad couture dress, Anita Ko jewelry, Neil Rodgers shoes.

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Some guests - such as Rihanna and Jessica Alba - decided to break from their usual norm and possibly swapped outfits backstage prior to strutting the line... Here's Rihanna in Thierry Mugler and Alba in a rather more rock 'n roll Zuhair Murad number. 

Black lace was definitely a thing last night, with Britney Spears, Demi Lovato (Chanel), and Lady GaGa's biggest fan, Laverne Cox (Michael Costello) and Heidi Klum (Alfredo Villabla) heavily embracing the barely there material / gaffer tape... 

 

Bringing bolts of blue to the sea of black we have Ariana Grande in Versace... 

She looks cool as a cucumber given she nearly floored herself before a red carpet interview...

Metallics weren't that prolific, with Ciara being the only one in slinky silver thanks to Philip Plein.

Meghan Trainor also brought a bit of spangle in Michael Costello...

The only person who went with white was Kate Beckinsale in Melina Dzinovic.

And breaking all the moulds, we have Ke$ha in Nudie Suit...