Mistress expecting Tristan Thompson's child, alleges star cheated on Khloe Kardashian

In a shocking development Tristan Thompson is once again becoming a father but his on and off girlfriend Khloe Kardashian is not the mother.

In court documents obtained by Daily Mail, Tristan had an alleged fling with a personal trainer Maralee Nichols.

The mother of the basketball star’s baby is suing the star for child support.

The 31-year-old was snapped visibly heavily pregnant as she is reportedly ready to give birth on December 3.

In the documents, it is stated that the baby was conceived in Houston, during the basketball star’s 30th birthday celebrations.

He was still dating Khloe, who he shares a daughter True Thompson with, at the time.

In a declaration, Tristan admits to having sexual relations with Maralee, who claims that their affair began five months before his birthday.

Furthermore, the documents added that she traveled "to California on multiple occasions, and continued after she got pregnant".