IF you’ve had a bellyful of Brexit here’s a new In/Out debate.

With celebs flaunting their taut tums in bikinis and crop tops, you may have noticed that belly buttons fall into distinct types.

Some stick out, others sink in, and Emily Ratajkowski’s inbetween affair proves that even supermodels aren't perfect.

Their shape can even give away whether the owner once had a piercing or even a nip/tuck.

Here, if you can stomach it, JENNY FRANCIS goes navel-gazing and reveals the button bunches . . .

Innies

Kelly Brook looks every inch the Bond girl in a stripey bikini

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Kelly Brook looks every inch the Bond girl in a stripey bikiniCredit: Insight News and Features

THE most discreet type of all, an innie doesn’t show any wrinkly skin – just a darker hole in the middle of the tummy.

Reality TV star Kim Kardashian, 35, and model Kelly Brook, 36, are both in the innies crowd.

Kim Kardashian bares all in an unusual fur bikini

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Kim Kardashian bares all in an unusual fur bikiniCredit: Xposure

So too are pop star Katy Perry, 31, and singer and actress Selena Gomez, 24.

Outies

Gigi Hadid's outie was evident in this crop top

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Gigi Hadid's outie was evident in this crop topCredit: Splash News

STICKIE-outie belly buttons come in all shapes and sizes.

This protruding type shows everyone a little more than they’d like to see.

Model Gigi Hadid, 21, popped hers out on the way to a photoshoot in New York recently. And in her wilder Ginger Spice days Geri Horner, 44, often got her outie out.

Geri Horner often showed off her outie back in her Spice Girls days

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Geri Horner often showed off her outie back in her Spice Girls daysCredit: The Picture Library Ltd.

Other famous outies include actress Katie Holmes, 37, and American Black Eyed Peas singer Fergie, 41.

Inbetweenies

Emily Ratajkowski is one star with an inbetweenie bully button

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Emily Ratajkowski is one star with an inbetweenie bully buttonCredit: Instagram

THE inbetweenie is the floating voter of the belly button world – it just can’t decide if it is in or out.

Emily Ratajkowski, 25, showed hers while modelling swimwear in yesterday’s Sun.

Abbey Clancy is anotehr whose belly button isn't quite sure if it's in or out

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Abbey Clancy is anotehr whose belly button isn't quite sure if it's in or outCredit: Fame Flynet

Also in Emily’s gang are model Abbey Clancy, 30, telly’s Myleene Klass, 38, and actress Gwyneth Paltrow, 43.

Rebellies

Helen Flanagan bares the evidence of a former belly button piercing

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Helen Flanagan bares the evidence of a former belly button piercingCredit: Splash News

HAVING your belly-button pierced is the ultimate “I’m not a kid any more” statement.

But when you grow out of being a wild child and ditch the metal belly bar it leaves a little round reminder of your rebellious teens.

Jessica Alba may have outgrown her piercing, but the scars won't let her forget it was there

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Jessica Alba may have outgrown her piercing, but the scars won't let her forget it was thereCredit: Xposure

The rebellie bump is evident in Helen Flanagan, left, singer Miley Cyrus, 23, actress Jessica Alba, 35, Little Mix’s Leigh-Anne Pinnock, 24, and reality star Amy Childs, 26.

Mini

Cute as a button... Millie Mackintosh took to Instagram to show off her mini

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Cute as a button... Millie Mackintosh took to Instagram to show off her miniCredit: Xposure

AS the name suggests, minis are tiny, barely visible navels that are cute as a, well, button.

Major stars who have been flaunting their minis in bikinis recently include ex-Made In Chelsea’s Millie Mackintosh, 27, and pop star Taylor Swift, 26.

Taylor Swift also has a mini belly button

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Taylor Swift also has a mini belly buttonCredit: Barcroft Media

Other mini celebs include actress Keira Knightley, 31, and Girls Aloud singer ­Kimberley Walsh, 34.

RELATED STORIES

Nip/tuckies

Any chance you've been under the knife, Demi Moore?

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Any chance you've been under the knife, Demi Moore?Credit: Fame Flynet

IF you don’t want to admit to going under the knife, keep your belly button under wraps.

A stretched, misshapen-looking belly button can give the game away, and may indicate the owner has resorted to a little nip/tuck.

Courtney Love is another whose belly button may give away evidence of a nip and tuck

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Courtney Love is another whose belly button may give away evidence of a nip and tuckCredit: Pacificcoastnews.com

Anything you want to tell us Demi Moore, 53, rocker Courtney Love, 52, and designer Donatella Versace, 61?

Nonies

And then there's Karolina Kurkova, who just doesn't really have a belly button at all

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And then there's Karolina Kurkova, who just doesn't really have a belly button at allCredit: Alpha Press

THE rarest of all belly button types is the nonie, where the navel is practically non-existent.

In fact, the only celeb member of this select group is Czech Karolina Kurkova, above. The 32-year-old underwear model, once a Victoria’s Secret Angel, has even had a fake belly-button airbrushed into her photos in the past to make her appear “more normal”.