Kim Kardashian West assumed Caitlyn Jenner would spell her name with a K.
The 72-year-old reality star changed her name in 2015 after coming out as trans and she recalled a funny conversation with her stepdaughter - whose siblings are Khloe, Kourtney and Rob Kardashian and half-siblings are Kendall and Kylie Jenner - about how she wanted to be known while discussing her new identity.
Speaking on 'Big Brother VIP', Caitlyn - who was previously married to Kim's mother Kris Jenner - said: "Kimberley goes, 'Well what am I going to call you?' And I said 'Caitlyn'. And she looks at me and says, 'Ah, I'm glad you stayed with the Ks.'
"My other kids, Kendall and Kylie, I am biologically their father, and they said you know, 'Well what do we call you?'
"And I thought for a second, and I said 'dad'. I'm never going to be your mother."
The former Olympian - who also has Burt and Cassandra with first wife Chrystie Scott and Brandon and Brody with second spouse Linda Thompson - confirmed her kids still call her "dad" and praised them for being consistent in their use of the correct pronouns.
Asked by one of her housemates what her children call her, she replied: "Um, yes they still call me dad.
"But what my kids are so good at, it's – every time they do it; [they say] 'My dad, she did this'.
"They change pronouns right kind of in the middle. And every time I hear it I go, 'Kids got it, they got it'."
Caitlyn recently admitted she wishes she had a "closer" relationship to Kris.
She said: "I would say from my standpoint, our relationship is not as good as it should be.
Asked if she thinks Kris has any misgivings about her, she added: "I think that is an understatement."
The 'I Am Cait' star wishes they got on better for the sake of their daughters, Kylie and Kendall.
She continued: "Our relationship is okay. I think it could be better just because of the kids. It's always the way when you have that. It's all about how the mother and father, how they get along together. Is it easy? Is it good? Do they see each other? Is there any tension?"