How bra-zen of you! January Jones shows off cleavage in sexy open suit at the Hammer Museum's annual gala

He most famous role is the buttoned-down Betty Draper.

But on Saturday night January Jones didn't even wear the shirt.

The 38-year-old wore a sexy black two-piece suit to the Hammer Museum Annual Gala, with her matching black bra on display.

Keeping up the Jones! January showed off her bra is sexy open suit at the Hammer Museum's annual gala on Saturday night

Keeping up the Jones! January showed off her bra is sexy open suit at the Hammer Museum's annual gala on Saturday night

The X-Men actress left the jacket unbuttoned, flaunting platy of cleavage along with her toned tummy.

Her famous blonde tresses were combed back to also showoff her flawless make-up, highlighting her perfect cheekbones.

January shared a closer look at her awesome make-up job on Instagram on the way to the event, flashing her icy blue eyes with a 'BOO!'. 

Among those joining her at the star-packed 14th annual gathering in Westwood was Isabel Lucas, Jodie Foster, Amanda Peet, Sarah Paulson, Emma Roberts, Alessandra Ambrosio, Alexandra Hedison, Sarah Williams and Joel McHale, Tom Ford, Mamie Gummer, Andie MacDowell, Laura Dern, Selma Blair, Jane Lynch and Mischa Barton.

Confident: The X-Men actress left the jacket unbuttoned, flaunting platy of cleavage along with her toned tummy

Confident: The X-Men actress left the jacket unbuttoned, flaunting platy of cleavage along with her toned tummy

On display: Her famous blonde tresses were combed back to also showoff her flawless make-up, highlighting her perfect cheekbones

On display: Her famous blonde tresses were combed back to also showoff her flawless make-up, highlighting her perfect cheekbones

The actress revealed recently at an AOL interview why she is so private on social media, as well as the very famous name who advised her to do so.

'My sister is my social media guru. She's the one who made me do Instagram. I wasn't relevant, apparently. She thought it would be good to show a different side of my personality because I've always been so private,' she said. 

'This is going to sound pretentious, but Jack Nicholson told me once that I shouldn't do interviews or give people any insight into who I am,' she added. 'He said to keep as much as you can private so they believe you in the characters you play.'

'My family did not choose the business that I chose. If I post a picture of them, I ask first. They want to maintain their privacy.'

The mother of one has not even revealed the identity of the father of her son, Xander. 

Piercing: January shared a closer look at her awesome make-up job on Instagram on the way to the event, flashing her icy blue eyes with a 'BOO!'

Piercing: January shared a closer look at her awesome make-up job on Instagram on the way to the event, flashing her icy blue eyes with a 'BOO!'

 

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