New England Patriots player Bret Lockett better hope he's telling the truth about his alleged five-month affair with engaged reality star Kim Kardashian. The NFL player has been telling just about anybody -- and everybody -- who will listen that he was shagging the E! star while she's been with fiance Kris Humphries. Just yesterday he appeared on TMZ Live and told the crew that he's been having an online and physical relationship with the brunette beauty since earlier this year. Ironically, he dodged questions about any evidence he may have supporting his claims. As for Kardashian, she maintains she's never even met the baller, making the situation even more frustrating. Kardashian warned Lockett that she would pull out the legal guns if he kept talking smack, and now that's just what she's doing. In a letter to Lockett, Kardashian's lawyer Michael Kump writes, "To put it very plainly and clearly, and as Mr. Lockett knows, there is not now, and never has been such a relationship. Ms. Kardashian does not know and has never even met Mr. Lockett." Kardashian wants Lockett to take back everything he's said and to stop talking to trash. If he doesn't stop, the next person the football player will be defending is himself. Kardashian wasted no time blasting Lockett on her blog and calling him out for the liar he supposedly is. She writes, "I knew when I got engaged that rumors and false stories were going to start, but this is RIDICULOUS!!!! This guy should be ashamed of himself. Calling up a magazine and making up an entirely fake story in a sad attempt to ruin my relationship!?!?! It's just shameful and this guy should feel ashamed and humiliated. Is this your pathetic attempt for attention? I'll be damned if anyone, especially some loser I've never even met, is going to try to come between Kris and me...The tabloids and weekly magazines will do ANYTHING to sell copies, and in this case they decided to run a false story, knowing they had absolutely no proof that it was real. It's disgusting, and I will be taking legal action against InTouch magazine and Bret Lockett."