Kourtney Kardashian has been hit with a demand from a model claiming he had a fling with her and demanding she submit her son Mason to a paternity test.
He has written Kourtney a letter claiming he is the father of her three-year-old Mason and demanding he has a DNA test.
The letter, printed in US magazine Star, reads: "This is Kourtney's last chance. My next step will be to take her to court and sue her for a paternity test. I'm tired of not knowing if Mason is my child, and I want the constant wondering to end."
Kourtney, 34, is yet to comment.