Darkest Kardashian secrets: Sex tapes, rehab, cheating, surgery and fake scenes

 Keeping Up With The Kardashians cast. (Courtesy)

Keeping Up With The Kardashians has kept the world entertained and enthralled since 2007.

The Kardashian-Jenner clan vowed to play out their lives - good, bad and ugly - in front of the cameras.

But what are they hiding from us?

Despite their open and honest policy, there are things they'd rather we didn't know, and there have been plenty of cover ups over the years.

They might have denied a lot of things, but many still don't believe them.

Here's a look at 14 of the Kardashians' darkest secrets ahead of the last ever episode of KUWTK this week...

Did Kris leak Kim's sex tape?

The story behind how KUWTK got the green light depends on who you believe.

Caitlyn says the show was essentially built around her fame as an Olympic hero, while Kris says she landed the show after approaching producer Ryan Seacrest after a pal gave her the idea.

Either way, right from the off, Kim was the star of the show.

And it just so happened that the sex tape she'd recorded with then-boyfriend Ray J in 2002 was leaked in 2007, just months before the show was created.

Many people believe that it was Kris herself who leaked the sex tape, in order to gain notoriety for her daughter and the rest of the family.

Whoever is behind the leak, it brought the family unimaginable fame and fortune.

Khloe faked trying to have a baby with Lamar

Khloe and Lamar's relationship seemed like a fairytale.

They got married just 30 days after they met, with Khloe recruiting momager Kris to plan the wedding of her dreams in just a matter of days.

But while they appeared to be living love's young dream, things weren't all they seemed.

Khloe and Lamar were married for seven years, and she spoke of how much she wanted to have children - biological, adopted and fostered - with the basketball player.

But after their marriage broke down, she admitted she'd been faking it, and was actually taking measures to prevent herself from getting pregnant.

She said: "I was married, but I knew the circumstances weren't the healthiest. So, I just kept pretending I was doing it."

Khloe did have fertility treatments while she was married, but stopped them.

She added: "I had to stop because there was much deeper stuff that was happening in our marriage.

"I knew that it wasn't the right situation to bring a child into, and I think I've done a lot of covering up for him."

Lamar later said he was hurt by the revelation, as he'd found out along with the rest of the world when it was aired on their show.

Lamar's drug use and cheating

Unknown to Kardashian fans at the time, Lamar had some serious drug problems and regularly cheated on Khloe.

And Khloe admitted on the show she had done all she could to hide the truth.

She said: "The way I was living is not a way to live!

"I kept in hiding every time there was something going on. I would have to lie, or conceal, or cover up, and I'm so over it!"

Khloe was even forced to lie that she was with Lamar during one of her birthdays, when in fact he was with another woman.

Lamar came clean about his bad treatment of Khloe in 2017, one year after their divorce.

He told Us Weekly: "If there is one thing I regret when I was married, it was having multiple affairs with different women.

"That wasn't the stand-up thing to do. I wish I could have kept my d**k in my pants."

Lamar had a severe drug problem and almost died in 2015 when he overdosed on substances, including cocaine and herbal viagra, at a brothel in Nevada.

He was in a coma and experts were worried that he'd suffered brain damage due to a lack of oxygen after he lost consciousness.

Khloe later said she'd been told he only had four hours to live.

Khloe had filed for divorce from Lamar in 2013, but as it was never signed off she was still his next of kin.

She flew to Vegas to be by his side as he fought for his life, despite everything that had gone on between them behind the scenes.

Kylie lied about lip injections

Kylie started getting lip fillers when she was 16, but lied about it for a long time, claiming that it was just clever make up hacks that made her lips look so much bigger.

She was quizzed about it repeatedly, and stood firm on her denial, insisting she overlined her lips to give them their fuller appearance.

She released her own make up line, Kylie Cosmetics, that became so popular she was named Forbes magazine's youngest self-made billionaire two years in a row.

But she later confessed all.

She said: "What if I came out and said, 'Oh, yeah, I got my lips done?' What are those moms going to think about me?'

"These kids, my fans, they're going to think I'm crazy. I didn't want to be a bad influence. I didn't want to think you had to get your lips done to feel good about your face. But they thought it was crazier that I was lying about it because it was so obvious. I wish I had just been honest up-front."

And she admitted that she'd gone too far, adding: "When you first get them done, you're like, 'Oh, it could be a little bit bigger on that side.' I'd go back and be like, 'They went down' and think they could be bigger. But I went too far."

Rob hid weight gain and diabetes troubles

Rob, the only Kardashian son, was a regular on the show, and even had his own spin-off with then-girlfriend Blac Chyna, before he suddenly disappeared.

His family members spoke briefly about how he no longer wanted to feature on screen due to his weight gain.

But there was a lot more to it than that.

Rob was diagnosed with diabetes in 2015 and was even hospitalised with it on some occasions.

He became a recluse after gaining weight, and is reported to have weighed as much as 300lbs at one point.

It's thought that it was the stress of his drama with Chyna that caused him to gain weight, in turn affecting his diabetes.

Just months before being hospitalised, he had told People that Chyna had cured his diabetes.

He said: "She told me that by having her cook for me, my diabetes would be gone. And it is."

Kendall's battle with anxiety

Kendall might be storming it in the fashion world, but behind the scenes, she's suffered a lot.

Kendall revealed in 2016 that she'd been secretly battling stress and anxiety that gave her both panic attacks and sleep paralysis.

She said: "I'm freaking out because recently I wake up in the middle of the night and I can't move.

"I'm done arguing with people because everyone says I'm fine, but I don't feel fine. And I promise you one day when I'm rushed to the hospital then you guys are gonna wake up."

Kris ended up getting a therapist for Kendall, and once had to fly with her daughter from Los Angeles to London just so she'd feel comfortable on the plane.

Kendall since says she's learned about breathing exercises which help her cope with her anxiety.

Scott's many trips to rehab

Kourtney's ex and father of her children Scott Disick was seen struggling with his drinking problem on the show.

In one unforgettable scene, he shoved a $100 bill down a waiter's throat after having his alcohol supply cut off.

Behind the scenes, Scott actually spent four spells in a rehab facility to battle his addiction.

Kanye's health problems

Kanye West's world began to fall apart after his wife Kim was robbed in a terrifying ordeal in Paris.

He cancelled his tour and checked into UCLA Medical Center to get help amid claims he was suffering from exhaustion and sleep deprivation.

There had been signs that something was up in the weeks leading up to his hospital admittance, including a number of onstage rants that saw the rapper take aim at old pals Beyonce and Jay-Z for their response to the news of Kim's ordeal.

It was later reported by TMZ that Kanye's breakdown was caused by a mishap in the dosage of his medication.

The site said Kanye sufferes from psychological issues, which are controlled by medications.

Kanye later confessed he has bipolar, and that his symptoms can sometimes leave him feeling paranoid about his surroundings.

Claims that the show is fake

The show has forever faced fake claims.

Many people believe that a lot of scenes in the show are set up, and that storylines are created to keep viewers hooked.

One of the moments said to be completely fake was Kim's infamous reactions to losing one of her earrings while on vacation in Bora Bora.

Her beau Kris Humphries picked Kim up and threw her into the water, and she had an absolute meltdown when she lost one of her diamond earrings.

The entire family ended up frantically searching for the missing jewellery, and Kim's over-the-top reaction got everyone talking.

But it's been claimed that the whole thing was fake.

It's said that Kim never lost her earring and the whole thing was created as a publicity stunt for the show.

It's also said that Kim's three-month marriage to basketball player Kris was all staged to drum up viewers, and it's claimed his 'surprise' proposal was actually shot twice so that the camera crew could get all the angles they needed.

Of course, the family insists everything we see on their show is real.

Caitlyn hid her gender identity issues - and did Kris know?

Of course Caitlyn's transition from Olympic hero Bruce is widely known now.

But for years, she hid her gender identity issues, taking on the role of the family's submissive patriarch.

Caitlyn battled her whole life after realising she was a woman trapped inside a man's body, and says that she even took up athletics in a bid to hide her true gender.

When her children Kylie and Kendall were just young girls, they even caught their dad dressed up in women's clothing on camera.

Caitlyn has told the story of how Kendall set up a camera in her room to record Kylie, believing she was stealing her clothes, and when she watched the footage back, she saw her dad come into her room dressed as a woman to check himself out in the mirror.

Caitlyn, who officially became her true self in 2015, wrote about her lifelong struggle in her 2017 autobiography The Secrets Of My Life.

She confessed that while touring the country giving motivational speeches after her 1978 Olympics victory, she used to pack women's clothing so she could secretly dress up and head down to the hotel lobby for fleeting moments as the real her.

She wrote: "That I am not Bruce Jenner but a woman I will come to call Caitlyn, who still has to be Bruce except for stolen moments where I can be my authentic self. The speech that I give is called 'Finding the Champion Within.' All bulls**t."

Whether or not Kris knew Caitlyn's secret is something they'll always disagree on.

Kris insists she had no idea, but Caitlyn says she told her early into their relationship and that she even had a special hiding space in the closet for her clothes in agreement with Kris.

Is Kim's bum real and has she had plastic surgery?

Kim has faced a number of allegations that she's had plastic surgery thanks to her changing looks over the years.

But she insists she's never had more than simple botox.

In a bid to prove that every inch of her is the real deal, Kim once had her famous bum X-rayed to show that there were no hidden helpers tucked away inside.

She insists her figure is all natural.

Kris Jenner's house wasn't even hers

When the show first began, the action all revolved around Kris' home.

But it turns out that it wasn't actually her house. And we don't just mean that she didn't own it - she didn't live there!

Kris actually lived 20 miles away from that house, which has also been featured on fictional shows American Horror Story and True Blood.

Fans finally clocked onto it years later when it went up for sale, and Kris wasn't the one selling it.

Kim's involvement in the OJ Simpson murder trial

Way back before they were famous, the family was involved in one of the most high-profile court cases the world has ever seen.

The girls' father Robert was on OJ Simpson's defence team as he faced trial for the murders of his ex-wife Nicole Brown Simpson and her friend Ron Goldman.

The case tore the family apart, with Kris believing her best friend Nicole had been murdered by her ex, and Robert believing he was innocent, and trying to prove it.

But one thing people may not know is that Kim was mentioned during the trial.

It turned out that at some point after the murders, and when Simpson was officially a subject, he obtained a gun and crept into Kim's bedroom to stow it away and threatened to hurt himself.

Robert talked him down, begging him not to hurt himself in his daughter's bedroom.

The scene was recreated in American Crime Story: The People Vs OJ Simpson.

Is Khloe really a Kardashian?

Khloe has forever faced claims that she's not really a Kardashian.

Because she doesn't bare as much of a resemblance to Kim and Kourtney as they do to each other, people became convinced that Kris' ex Robert Kardashian wasn't actually her biological father.

The most popular theory is that OJ Simpson is her dad.

Of course, they've always denied this, but it didn't stop the theories.

OJ himself has since spoken out about it - after being released from prison.

He said in a Twitter video: "My life has always been involved in the sports world and I suspect as the weeks go on that's pretty much what I'll be talking about, but once in a while I'm going to go off topic and talk about something else and this is one of those times.

"You know, Bob Kardashian, he's like a brother to me, he's a great guy. He met and married Kris and they really had a terrific time together when they were together.

"Unfortunately that ended, but never, and I want to stress, never in any way, shape or form have I ever had any interest in Kris, romantically, sexually, and I never got any indication that she ever had any interest in me.

"So all of these stories are just bogus, bad, tasteless. Khloe, like all the girls, I'm very proud of, just like I know Bob would be if he was here, but the simple fact of the matter is she's not mine.

"Now, one of the people spreading this rumour is a guy the media loves to say is my manager."