Reese Witherspoon says Chelsea Handler is a "wild card".
The actress is currently promoting her new movie This Means War and spoke about her co-stars and what it was like to work with them.
The action-packed rom-com is about two CIA operatives, played by Tom Hardy and Chris Pine, who get into an epic battle with each other after they find out they are dating the same woman, played by Reese.
Comedienne Chelsea also stars in the spy film.
"The movie is this great female fantasy, where you have these two amazing guys chasing around after you. And honestly, you don't know who she'll pick until the very end, so it's exciting," Reese told Cover Media at the London premiere of This Means War, before talking about co-star Chelsea. "She's got a fire in her. She's kind of a wild card, you don't know what she'll do. She was good, she managed to behave herself - sometimes."
Reese looked stunning as she walked the red carpet in a green sequined Louis Vuitton design.
The mother-of-two revealed how she keeps trim and toned.
The Oscar-winner lives on a converted farm in Ojai, California, with her family and credits their animals for keeping her in shape.
"I try to be healthy all the time, you know, I have chickens, so I run around after them. I exercise, I eat well..." she explained.
This Means War is released in the UK on March 2.