Jeff Lewis and Jenni Pulos Credit: Eugene Gologursky/; John Shearer/Getty

Jeff Lewis is flipping out!

The Bravo star has filed a lawsuit against his longtime assistant and reality show costar, Jenni Pulos.

In court documents obtained by toofab, the Flipping Out star, 42, claims Pulos' new book about her experiences as his assistant violates a confidentiality and non-disclosure agreement she signed in 2008 and 2010.

The suit charges that the book was originally titled, Hang in There, Baby: What One of the World's Most Difficult Bosses Taught Me About Life, Work and Love, but was later shortened to simply Hang in There, Baby.

Lewis is asking for "a preliminary and permanent injunction" against Pulos from "publishing any and all facts/or references to events . . . related in any manner to personal, private, property and confidential information."

On Thursday, Pulos tweeted, "Woke up this am, being sued by your boss is really putting on the Celebrity Cinderella Slipper, Bullies Aren't Cool."