'House' Divided! Co-stars Will Ferrell And Amy Poehler 'Can't Stand Each Other!'

Will Ferrell and Amy Poehler may seem all smiles as they promote their eagerly awaited rom-com The House, but sources tell RadarOnline.com there's no love lost between the comedy heavyweights.

"They wrapped this movie in less than four weeks – because they can't stand each other," says an insider. "They play a suburban couple who open an illegal casino in their basement, but any on-screen affection between their characters is acting at the highest level."

Ferrell and Poehler have a long history of trying to upstage each other on Saturday Night Live, and that apparently hasn't changed in their blossoming movie careers.

"They were always very competitive with each other, even after 20 years," our source said. "They agreed to work 20-hour days to make the film together as quickly as possible, and hardly ever spoke to each other when the cameras were not rolling."

In the new comedy, Ferrell and Poehler play a couple who can't afford to send their daughter to college. But pretending to be happily married was apparently award-winning acting.

"They aren't friends and the competition between them is as intense as ever."

Now the two are out promoting the movie together, but our insider says each can't wait for their forced confinement to be over.

"They're under strict orders from Paramount to play nice on the red carpet," the source revealed. "But the irony is the film's been getting rave reviews from early screenings and if it does as well as expected, they'll be pressured to pair up again for a sequel."