In Touch can exclusively reveal that Michael Girgenti is hauling Kourtney Kardashian to court on Dec.16, alleging that he could be the biological father of her 4-year-old son, Mason.

“I just want the truth to come out,” Michael says in the new issue of In Touch, on stands now. The reality star, 34, has vehemently denied hooking up with Michael, who claims he and Kourtney had a single steamy encounter in March 2009 after first meeting at a 944 Magazine photo shoot in August 2008.

According to Michael, 27, Kourtney came over to his LA apartment while on a break from her relationship with Scott Disick, 30, and they had unprotected sex. When Mason was born nine months later, he tells In Touch, “I began to wonder.”

Kourtney Kardashian Flips Out Over Scott Disick and Khloé Kardashian’s Close Relationship!

Kourtney tried to silence the LA-based model's accusations for good when she told the world in August that a DNA test proved Scott is Mason’s biological dad. But Michael won’t take Kourtney’s word for it — and he’s hoping a judge will order an independently administered test.

“At this point, I have nothing to say to her,” Michael tells In Touch. “But if I am the father, I need to be slowly integrated into Mason’s life before more time passes. If I’m not, I can rest at ease — and everyone can move on.”

For more, pick up the new issue of In Touch, on newsstands now.