Do not mess with Khloé Kardashian's family. The youngest Kardashian sister is always the first to fiercely defend any member of the Kardashian/Jenner clan, and this time the reality TV star slams her stepmother for spreading the rumor in 2012 that Khloé is not the biological daughter of the late attorney Robert Kardashian.

Khloé has been very open about her life during previous episodes of her new, hit FYI late night talk show "Kocktails with Khloé." In last week's episode, she opened up about her ex-boyfriend, NBA star James Harden's infidelity which led to their break up and she spoke about how her mother Kris Jenner's affair affected Robert and how it affects Khloé's relationships as an adult.

In a sneak peek for the Wednesday (March 9) night episode which features dancer Cassie and actors Slink Johnson, Alec Mapa and Vivica A. Fox as guests, Kardashian calls out her stepmother for spreading lies about her father almost 10 years after his death.

"I feel like you're one of the most exposed celebrities we have right now," Mapa tells Kardashian. "There's so much about you that's out there that leaves you vulnerable. How do you handle that?"

"I think the thing that most became overwhelming was when the stuff happened with one of my dad's wives," Khloé responds with a laugh. "She wanted to come out like 10 years later after my dad passed away and say that I'm not his daughter and he confided in her and blasé blah. But I was like listen, you could talk about me and my sisters all you f--king want, do not talk about my dad."

"Yeah, he can't defend himself," Fox says off-camera.

"Right, he's not here," Khloé agrees.

Khloé referenced a 2012 tabloid exposé that allegedly featured interviews with Robert's former wives, Jan Ashley and Ellen Pierson. In the story, both women came forward and said the late defense attorney for O.J. Simpson told them that Khloé is not truly a Kardashian because is not biologically his child. After the story was published, Khloé hit back at both women via social media.

"The audacity you have to mention my father's name like this! Should be ashamed of urself! I let a lot of things slide but this one is really low... YOU ARE DISGUSTING! (yes you know who YOU are)," Khloé wrote on Twitter.

Watch the full sneak peek below and be sure to catch tonight's episode of "Kocktails with Khloé" airing at 10 p.m. on FYI.