Blake Griffin Filed for Paternity Against Ex-Fiancée After Hooking Up With Kendall Jenner

Blake Griffintook the first shot in what could be a nasty custody war with the mother of his two children, and it all centers aroundKendall Jenner.

According to our sources, Griffin recently filed paperwork to legally establish paternity of Finley and Ford, the kids he has with ex-fiancée Brynn Cameron. Filing for paternity is the first step in getting a court ordered custody and child support agreement, and Griffin filed the documents shortly after he began dating Kendall Jenner.

We're told Cameron actually fired off her own documents filed by powerhouse attorney Samantha Spector in response to Griffin, again seeking joint custody, but also asking the judge to establish child support based on Griffin's annual salary.

Child support is established based upon income, and Griffin recently signed a $173 million deal with the Los Angeles Clippers, so there's a good chance she'll get a giant monthly payment. There's also a good chance Griffin will argue the amount.

Getting back to Kendall, as we previously reported, Griffin split in July, but she only moved out of the couple's home after Griffin took his relationship with Jenner public.

We're told Cameron's position is that Blake walked out on his family for a glamorous Hollywood relationship with Kendall Jenner, and she's going to ensure that he doesn't leave his other family out in the cold.