Kourtney Kardashian is facing a legal battle after model Michael Girgenti has filed a paternity lawsuit in Los Angeles, claiming he is the father of her first child, Mason. He is reportedly seeking joint custody, after alleging he had sex with her in March 2009, nine months before the reality star had Mason.

Kardashian, 34, has denied the allegations, with her lawyer telling InTouch magazine back in March, "They did not exchange contact information. Since the Aug. 20, 2008, on-set photo shoot, Kourtney never spoke with him, saw him nor met him again. Kourtney has never been alone with him, and Kourtney certainly has never physically/intimately been with Mr. Girgenti.”

In a letter dated April 23, 2013 he threatened to sue her if she does not allow a DNA test to be taken. “My attentions are not to hurt the family you’ve created with Scott. But at the same time, Mason deserves to know the truth. I assure you that I don’t take being a father lightly. I will be a great father to Mason. Please take this final request for a DNA test seriously, because if you don’t, I will be forced to take legal action and sue.”

It seems Kardashian refused for a DNA test to be taken, as Girgenti has since taken legal action.

The Chicago native spoke with InTouch in March about their alleged sexual tryst. "We started kissing, making out and touching each other. My shirt was off. We were fooling around on the couch a little while before I took her to the bedroom.”

The 26-year-old model then says he and Kardashian undressed and were intimate and did not use protection, as he assumed she was taking birth control. She and her longtime boyfriend, Scott Disick, were on a break during this time, he says. Girgenti claims he tried to contact Kourtney after the March 2009 encounter, but he was continuously ignored. 

The Kardashian sister gave birth to Mason Dec. 14, 2009. Kardashian and the Los Angeles-based model worked together in 2008 on a “944” magazine photo shoot. "I would definitely want to acknowledge Mason if he's my kid," Girgenti said, according to The Daily News. "He deserves to know his real father."