January Jones strips to her underwear and a vest as she flashes pert derriere in a tongue in cheek belfie

She played demure Betty Draper in Mad Men.

Yet January Jones has shed her good girl image once and for all as she shared a racy snap with her 496,000 Instagram followers on Wednesday. 

The 38-year-old actress showed off both her incredible figure and riotous sense of humour as she posted a side-by-side image of an adorable baby and her in her knickers. 

Scroll down for video

Stunner: January Jones has shed her good girl image once and for all as she shared a racy snap with her 496,000 Instagram followers on Wednesday

Stunner: January Jones has shed her good girl image once and for all as she shared a racy snap with her 496,000 Instagram followers on Wednesday

January looked incredible in the sexy image, as she posed in just knickers while snapping the image in a mirror from behind. 

She flashed a peace sign at the at the camera while flaunting her svelte frame in a grey vest, which clung to every inch of her stunning figure. 

The South Dakota-born beauty pulled her best pout as she pulled the same pose as the black and white image of the baby in the shot beside her. 

January appeared to go make-up free in the image which was taken in front of a luxury bath tub, in a stunning looking room. 

Snap happy: January's selfie-snapping antics, come after January officially announced last month in Paris that she's the new face of the Kérastase Nutritive collection of hair care products

Snap happy: January's selfie-snapping antics, come after January officially announced last month in Paris that she's the new face of the Kérastase Nutritive collection of hair care products

Her short blonde tresses were styled into loose waves, which were slightly muzzed - alluding to the fact she had snapped the image without much thought.

The baby in the coinciding shot was pulling the same pose and looked simply adorable with rolls and rolls of baby fat making for a cute shot. 

She captioned the shot: 'Who wore it best? #needmorefollowers #applebottoms' 

January's selfie-snapping antics, come after January officially announced last month in Paris that she's the new face of the Kérastase Nutritive collection of hair care products.

Humorously posing in front of a billboard ad she wrote on Instagram: 'Found this chick in Paris, she's cute eh? This poster is giving me a big head. I tried to bring it home in my carry on,' she added of another snapshot.

Hairy situation: Humorously posing in front of a billboard ad she wrote on Instagram: 'Found this chick in Paris, she's cute eh? This poster is giving me a big head. I tried to bring it home in my carry on,' she added of another snapshot

Hairy situation: Humorously posing in front of a billboard ad she wrote on Instagram: 'Found this chick in Paris, she's cute eh? This poster is giving me a big head. I tried to bring it home in my carry on,' she added of another snapshot

Say it in stripes like January Jones in Monse

January Jones seemed rather chuffed with herself as she noticed a Keratese poster plastered with her face while she was out and about. So much so that she uploaded a snap of her with it to Instagram.

In the photo the model donned a cute striped dress with a quirky tie sleeve waist that is quite a favorite design finish of Monse.

The designer brand sent January's exact dress down the autumn/winter 2016 runway so she's well ahead of the curve wearing it this spring.

You of course cannot buy this piece just yet, but why not click right to shop Monse's current line at Farfetch now?

If you're all about those stripes, then get ready to embrace them in one of the dresses in the line up below - they're all perfect for summer and will look fab with a pair of gladiator sandals.

* PRICES MAY NOT BE AS ADVERTISED

And while her hair is consistently on trend, earlier this month Jones opened up about her unique sense of style to Refinery29.

She said: 'One year at Met Ball, [the theme] was punk and I did a bleached eyebrow and Swarovski crystals, and my hair was in braids. It was a very severe look, and even my own parents were like, "What happened?"'

Adding: 'But I loved it and I felt super-bada**, so if it evokes a feeling of confidence in you [do it].'

January retired her role as Betty Draper last May on the AMC hit Mad Men but she has since been starring as Melissa Chartres in the Fox series The Last Man on Earth. 

Betty: January retired her role as Betty Draper last May on the AMC hit Mad Men but she has since been starring as Melissa Chartres in the Fox series The Last Man on Earth

Betty: January retired her role as Betty Draper last May on the AMC hit Mad Men but she has since been starring as Melissa Chartres in the Fox series The Last Man on Earth

 

The comments below have not been moderated.

The views expressed in the contents above are those of our users and do not necessarily reflect the views of MailOnline.

By posting your comment you agree to our house rules.

Who is this week's top commenter? Find out now