The Kardashians

Sources close to Kim K tell TMZ ... her lawyers are drafting a defamation lawsuit against Lockett and will file it as early as Monday morning.

Kim has maintained all along she never met Bret -- despite his claims they had a "physical relationship." Harvey hammered Lockett on TMZ Live last week, asking him when and where he met Kim, but Lockett refused to say. Nevertheless, he insisted he and Kim had hooked up this year, after she started dating Kris Humphries.

But on Friday, Lockett finally fessed up on "Showbiz Tonight" ... admitting he never actually met Kim.

We're told Kim's lawyers fired off a letter to Lockett in the last few days, telling him to hang on to the so-called "evidence" he has on his "affair" with Kim -- because he'll need to produce it in court.

What a jerk.

You'll remember ... we tried pressing Bret during TMZ Live earlier this week for details on where he met Kim ... but he

A story is circulating ... London helped facilitate the alleged Lockett/Kardashian hook-up by scoring Bret's number at Kim request. But an attorney for London fired off a letter to In Touch Friday, claiming London has had an impersonator for a while now, and if the mag spoke to anyone claiming to be her ... they were barking up the wrong tree.

The letter goes on to state emphatically that London "has never spoken to anyone at IN TOUCH WEEKLY, does not know Mr. Lockett and did not introduce him to Ms. Kardashian."

Kardashian has fired off a new demand letter to Lockett, obtained by TMZ, which warns him if he doesn't retract his allegations and cease from making fresh ones, his new position will be defendant on the left side of the courtroom.

Lockett went on TMZ Live Wednesday and insisted he did indeed have an online and physical relationship with Kim this year, at the same time she was dating now-fiance Kris Humphries.

In the letter, Kim's lawyer, Michael Kump, says, "To put it very plainly and clearly, and as Mr. Lockett knows, there is not now, and never has been such a relationship," adding, "Ms. Kardashian does not know and has never even met Mr. Lockett."

TMZ has obtained a demand letter, written by Kim's lawyer, threatening "In Touch" that if it ran the cheating story Kim would take legal action. The letter put "In Touch" on notice ... the cheating allegations "are, at a minimum, damaging, defamatory, and an invasion of her privacy."

Kim's reps tell TMZ ... Kim has never even met or spoken with Lockett.

Nevertheless, "In Touch" is publishing the story in its new issue. In the story, Lockett is quoted, saying, "I knew this was a game to her, and this is what she does." Lockett adds, "She pursued me."

Khloe was wearing a black shirt with see-thru material around the sleeves and part of her chest area -- and during the interview, her boob slipped into the see-thru section for all to see.

Nobody on the set seemed to notice -- but tons of viewers did ... and they bombarded Khloe's Twitter account with messages about the nip slip.

Kim Kardashian and her fiancé Kris Humphries are hedging their bets -- they're hammering out a prenup before they tie the knot ... TMZ has learned.

Sources close to the couple tell us … both Kim and her NBA star hubby-to-be are telling friends, “It’s the smart thing to do." And, by the way, they're right.

We’re told the move isn’t one-sided. Both Kim and Kris have tons of loot. Kim is worth a reported $35 mil.

As for Kris ... he's not only making $3.2 mil a year with the Nets, his family also owns a couple of burger joints in Minnesota. Kris' net worth is estimated at $8 million.

The ring -- designed by Lorraine Schwartz -- features a 16.5 carat emerald cut center stone flanked by two 2-carat trapezoids ... for a grand total of 20.5 carats.

We're told the stones are all "the highest clarity and color."

So, we gotta ask ...

Turns out, two music producers -- Terrace Martin and Devi Dev -- used a photo of a woman's bare chest on the cover of their album "Terrace Martin & Devi Dev Present: The Sex EP" ... and it just so happens the image was a close up from Kim's nude photo spread in W magazine.

Kim's lawyers fired off a cease and desist letter to Terrace and Devi demanding they swap out the pic -- and stated, "We cannot imagine why you thought you had the right to use this photograph without permission."

T and D immediately replaced the photo with another woman's bare bosom -- claiming they had no idea the original boobies belonged to Kim.

Sources close to Kim tell us she struggled with the decision to work with Cosmo again -- because even though she has an "amazing relationship" with the magazine ... she's very passionate about her Armenian heritage.

Kim was upset because Cosmo didn't ask her permission to run the controversial cover -- it's controversial because Kim is Armenian and the Turks committed genocide against her people nearly 100 years ago ... and still refuse to acknowledge it.

Fact is, Kim didn't even know about the Turkish magazine cover until TMZ posted it yesterday.

We're told Kim's team and Cosmo talked things out Monday and Kim decided to let bygones be bygones ... and another photo shoot could take place as early as this week.

Aram Hamparian -- executive director of the Armenian National Committee of America -- tells TMZ, "It's disrespectful to Kim Kardashian and to all Armenians for the publishers of Cosmopolitan to use her image, without her permission, on the month we mark Turkey's genocide against the Armenian people."

We're told Kim -- an Armenian-American who has been vocal about the genocide -- did an international photo shoot that went to various magazines published by Cosmo, but she didn't know it would end up on the Turkish version of the mag.

Sources say Cosmo let Kim's people know which international outlets of the magazine would use her picture -- but we're told Cosmo never mentioned Turkey to Kim or her reps. Our sources say Kim would never have approved the use of her pic in the Turkish version.

Rubbing salt in the wound ... April 24 is the day Armenians commemorate the genocide -- just weeks after her pic was splashed on the cover of Turkish Cosmo.

We contacted Cosmo for a statement ... and here's what they told us -- “Kim Kardashian is one of our favorite cover girls. We were thrilled to have the opportunity to photograph her for the Cosmopolitan editions worldwide.”

Geragos -- a friend of Kim K's -- tells TMZ ... Turkey seems to be on a campaign to co-opt L.A. Icons. First, Geragos says, the Turks used Kobe Bryant's image to promote Turkish Airlines, and now Kim.

Geragos says he believes the Kim K cover is a combination of taking advantage of a celebrity and rubbing salt in the wounds of a people who are the victims of genocide.