On Oct. 21, Kim Kardashian took to Alec Baldwin’s new talk show, The Alec Baldwin Show, where she revealed a number of personal insights on her life. Most notably, the mother-of-three confessed that she learned that her former step-father, Caitlyn Jenner, was transgender long before the 68-year-old came out to the world in 2015.

“I found out when I was maybe 25,” Kim began. “My mom was out of town and I walked in on Caitlyn all dressed up… as a woman in the garage at my mom’s house. I ran inside, packed a bag so fast, shaking, and ran out and called Kourtney [Kardashian].”

“I have to come spend the weekend with you,” the KUWTK remembered saying to her older sister at the time. “I was hysterically crying,” Kim continued. “She just was like, ‘What is it? Did you catch [Caitlyn] cheating?’ And I was like, ‘I wish. I don’t know what I just saw.’ I didn’t come home for the weekend.”

Kourtney Kardashian, Kim Kardashian West, Caitlyn Jenner and Kendall Jenner attend Kanye West Yeezy Season 3 at Madison Square Garden on February 11, 2016 in New York City
Kevin Mazur/Getty Images

Kim went on to explain that Caitlyn pleaded with her not to tell anyone. “One day I’ll sit down and I’ll explain this all to you, but until then, please don’t tell a soul and please don’t tell your mother. She’ll kill me,” the Olympic gold medalist said to her step-daughter.

Of course, Kim felt like she was stuck between a rock and a hard place. “I thought, ‘OK, if I tell her I’m going to break up their marriage and my little sisters aren’t going to have their dad around, so I better keep my mouth shut,’ ” Kim explained. “I didn’t say a word.”

The KKW Beauty mogul then expressed that despite whatever hardships her family experienced following Caitlyn’s coming out, that it was all for the best. “That’s why I love that we did share our story on our show because it gave people the understanding that you can have every different emotion and that’s okay,” Kim said. “At the end of the day, we just want Caitlyn to be happy and be herself.”