According to the 65-year-old US Olympic champion Kim told him, "Girl, you gotta work it baby, you gotta look good, if you're doing this thing, I'm helping you. You're representing the family. You gotta look really good."

While none of the Kardashian siblings or his youngest daughters, Kendall and Kylie Jenner, took part in the tell-all interview with Diane Sawyer, in which Jenner came out as transgender, he spoke of how Kim was the first who "caught" him dressing as a woman several years ago.

Jenner, who requested to have male pronouns used for the interview – his last as "Bruce" -  said Kim saw him dressed as a woman but the pair never discussed it.

"Kim caught me one time, walked in... She kind of walked out, jumped in the car and went for a drive. I tried to call her to ask 'hey are you OK?' but it was like this big secret in the house and we never talked about it again," he said.

It wasn't until tabloid articles began surfacing a few years ago that the pair spoke about his desire to transition. She then discussed the issue with West who told her, "I can be married to the most beautiful woman in the world, and I am. I can have the most beautiful little daughter in the world, and I have that. But I'm nothing if I can't be me. If I can't be true to myself they don't mean anything."

"Since them Kimberly has been, by far, the most accepting and the easiest to talk to about it," Jenner said.

The youngest of Jenner's 10 children, Kendall and Kylie, also discovered their father cross dressing but never spoke about it after Kendall, now a top model, believed her younger sister Kylie was stealing clothes so had surveillance footage recorded in her bedroom.

"It was the only full length mirror in the house," Jenner said after his daughters saw the video of him trying on dresses.

Understandingly, this has been very hard for me. You will hear what I have to say when I'm ready to but...— Kylie Jenner (@KylieJenner) April 25, 2015

..this isn't about me. I'm so proud of you, Dad. You are so brave. My beautiful Hero.— Kylie Jenner (@KylieJenner) April 25, 2015

Khloe​ has not been coping with the news after being told a few months ago.

Just finished watching the #BruceJennerInterview with the family. Bruzer, I'm soooo proud of you! Dads really are heros ❤️— Khloé (@khloekardashian) April 25, 2015

Jenner, who confirmed he identifies as a conservative Christian republican, told Sawyer he "always wanted to be a woman who kicked butt" but would like to be considered "asexual". The thrice married athlete also pointed out the differences between sexual desire and gender saying he's never "been with a man".

While he has begun hormone therapy, like he did for five years during the '80s following his world record in the decathlon at the 1976 Olympics, he said another marriage and sexual reassignment therapy will be "down the line". For now he is looking forward to embodying his true self, a person he calls "Her" and longs to wear nail polish long enough for it to chip off.

"I just want to have a free soul and have great friends. But if you're living your life as a female, you have to, as Khloe​ would say, you've got to have the 'vajayjay'," he said.

Jenner rose to fame again in the late noughties​ thanks to the reality series, Keeping Up with the Kardashians​, a deal brokered and produced by his ex-wife Kris Jenner, who also knew of his desire to become a woman.

He is no longer involved in the series, which is now in its 10th season.

"We had done 425 episodes almost over eight years now and the entire time I kept thinking to myself 'Oh my god, the one real true story about this family is hiding in me, it's the one story that could make a real difference in people's lives'."

Advocates for the lesbian, gay, bisexual, and transgender community applauded Jenner's bravery.

"Today, millions of people learned that someone they know is transgender," GLAAD president and CEO Sarah Kate Ellis said.

"By sharing this story, Bruce Jenner has shined a light on what it means to be transgender and live authentically in the face of unimaginable public scrutiny. Though Jenner's journey is one that is deeply personal, it is also one that will impact and inspire countless people around the world."