Caitlyn Jenner has claimed that she and her ex-wife Kris Jenner once cross-dressed together.

Caitlyn Jenner

Caitlyn Jenner

The 68-year-old television personality - who previously lived as Bruce Jenner and was married to the 'Keeping Up with the Kardashians' star for over 20 years until they split in 2015 - has admitted prior to marrying the Kardashian/Jenner matriarch and undergoing gender reassignment surgery she "dressed up" as a lady with the 62 year old, but only on "one occasion".

Speaking about her transition in an upcoming episode of 'Life Stories with Piers Morgan', Caitlyn said: "I definitely told her, I even dressed up with her before we got married, only on one occasion.

"I had been on hormones for four and a half years ... there are changes when you are on hormones which are tough to hide."

And though Kris has claimed she was left in the dark about Caitlyn's desire to transition into a woman, Caitlyn has insisted she was always "honest" with her former partner, even before the pair got intimate, although Caitlyn "downplayed" her feelings.

Caitlyn - who has Kylie, 20, and Kendall, 21, with Kris and Brody, 34, and Brandon, 36, with previous lover Linda Thompson as well as Burt, 39, and Cassandra, 37, with Chrystie Jenner - said: "I was honest to that point, I'm sure I downplayed it quite a bit but I was honest with her. I told her before I ever slept with her, she knew".

Although Kris knew about Caitlyn's gender identity issues, 'The Secrets of My Life' author has revealed that neither of them ever thought she would actually go through with the full transition.

Asked if Kris thought Caitlyn would carry out the numerous procedures to change gender, Caitlyn said: "No, neither did I."