Denise Richards admits that she had a hard time keeping a straight face while shooting the latest Tyler Perry film "Madea's Witness Protection."
"Nothing prepares you to see him as Madea," Richards said in an interview provided by Lionsgate, the studio behind the film. "This is the most challenge I've had on a movie in keeping a straight face in a scene."
"He [Perry] is so funny and the way he ad-libs and changes things," she added. "The stuff that just comes out of his mouth is really hilarious. So we have a hard time keeping a straight face."
In the film, Perry reprises his roles as Mabel "Madea" Simmons / Joe Simmons / Brian Simmons. Eugene Levy is George Needleman, a businessman who unknowingly takes part in a Ponzi scheme in New York City, which involved money from the mob. Needleman and his family have to go into the witness protection program and Madea's house in the south is chosen as the secret location.
Needleman and his wife (played by Richards), daughter, son and mother (played by Doris Roberts) all move into Madea's home. The film also stars rapper and actor Romeo Miller as the son of a preacher, John Amos and Marla Gibbs.
Richard also had kind words for her co-star and on-screen husband Eugene Levy.
"I love working with him, he's so fun to -- for us to play off of each other," the 41-year-old actress said. "He likes to rehearse so we sit in the bar and go over our lines the night before and he likes to talk about the scene and I love that in working with someone."
"It makes it so much more fun and easier and he's so great at comedy," she added.
"Madea's Witness Protection" hit theaters on June 29. Check out the trailer below.