Small and simple, by design they are unremarkable.

But Kim Kardashian's simple black buttons were the super heroes of her outfit on Friday - single-handedly saving the reality star's modesty.

The two fasteners were all that prevented onlookers getting an eyeful, just about holding closed the straining sides of her cropped cardigan as she went to lunch in New York.

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The hardest working buttons in New York! Kim Kardashian shows off her generous cleavage as she goes topless beneath a cropped cardigan

Just an ordinary lunch! Other diners seemed unimpressed, ignoring the media circus as the world famous reality star arrived

Self-confident Kim went braless beneath the tiny top - which she left mostly unbuttoned to better display her generous cleavage.

The cardigan was teamed with a white pencil skirt and an unusual suede bag, worn around the waist in the style of a money belt.

The tailored outfit certainly did the job of displaying Kim's gym-honed curves.

But she wasn't heading to a nightclub. Instead this was the outfit Kim chose for a quiet midday meet-up with her mother.

Stepping out: The cardigan was teamed with a white pencil skirt and an unusual suede bag, worn around the waist in the style of a money belt

Best dressed? Self-confident Kim went braless beneath the tiny top - which she left mostly unbuttoned to better display her generous cleavage

Deceptively modest: While Kris covered up for lunch, her top went sheer in the spotlight

And while it's not your ordinary 'lunch with mom' outfit, Kris Jenner is not your ordinary mother.

Momager to the entire Kardashian clan, she has master minded their rise to stardom.

For her meet-up with Kim on Friday (captured by the Keeping Up With The Kardashians cameras, of course), Kris chose a rather more modest all-black outfit.

The drinks are on me! A delighted fan bought Kim and Kris a glass of champers

Lunch! Kim shared a picture of her pasta dish to Snapchat

Long skirt, long sleeves and boots ensured there was barely any flesh on show - although the top did turn sheer in the flashlight.

Once inside the restaurant Kim Snapchatted her pasta dish, along with two glasses of champagne sent over by a fan.

She and her mom will have had plenty to chat about - they were dining days after it emerged that Kim is set to expand her family via surrogacy.

Mom to be: The 36-year-old and her husband Kanye West have employed the services of a surrogate, who is currently pregnant with a baby girl

The 36-year-old and her husband Kanye West have employed the services of a surrogate, who is currently pregnant with a baby girl.

The child is due in January - making the couple parents of three. The baby joins four-year-old daughter North and one-year-old son Saint.