Kate plays a royal gardener in the British period drama directed by Harry Potter star Alan Rickman.
In the chat, the 39-year-old mum-of-three explains how she dealt with her pregnancy while filming.
“I was pregnant when we were making this film so keeping the boobs in check was a challenge,” she revealed.
Regardless of her super-star status, the British bombshell explained that she still likes to give her all in awkward love scenes.
“If you’re doing a love scene you have to do it properly. Obviously you don’t do everything, but you have to commit!”
The Titanic star expressed appreciation for her character by adding: “She is feisty, she is headstrong and extremely bohemian and I fully intended to get as filthy dirty as I could.”
Despite getting “filthy dirty” the actress still had concerns about her body.
“I was pregnant and I did feel uncomfortable and unconfident.”
Kate praised her co-star Matthias Schoenaerts who made her feel relaxed during sex scenes, “He was very sweet and able to move me in ways that were favourable to my physical state”.
A Little Chaos is in cinemas now.
Watch Kate’s confessions in the video player above
