Kim Kardashian Accused of Cheating With Bret Lockett, Threatens to Sue In Touch Weekly

Normally, Kim Kardashian loves attention ... but not this kind of attention.

The professional celebrity is PISSED that In Touch Weekly is running a huge cover story claiming she has been cheating on her fiance, Kris Humphries.

They even name her supposed male mistress: NFL player Bret Lockett!

Kinky texts? Wild phone sex? Was Anthony Weiner involved?

Kim says she has never even met or spoken with Lockett ... but in the story Lockett is QUOTED PERSONALLY as saying that Kim pursued him, and that, "I knew this was a game to her ... this is what she does."

Yeah. Kim's rep says she's gonna be suing both In Touch and Bret.

A demand letter from Kim's lawyer has already been sent, threatening legal action and putting In Touch on notice, calling the cheating allegations "are, at a minimum, damaging, defamatory, and an invasion of her privacy."

The tabloid is running the story anyway. Lawyer up, In Touch.

THG POLL: What do you think? Did Kim have an affair?

[Photo: In Touch]