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Barbra Streisand and Seth Rogen play mother and son in the upcoming comedy The Guilt Trip, and their on-screen roles seemed to seep into their real lives during Nancy O'Dell's sit down with the movie stars.

WATCH: New Clip from The Guilt Trip

In observing how Streisand's maternal instincts came out around Rogen in the interview, Nancy was curious about how similar Streisand is compared to Rogen's biological mom.

"They're both very high-functioning people," Rogen said, drawing dubious looks from his co-star. "It means you're very aware of everything that's happening ... Nothing gets passed you."

Anne Fletcher (The Proposal) directs the flick which follows a young inventor (Rogen) and his mother (Streisand), who embark on a road trip together while trying to sell Rogen's new product. But each of them has an ulterior motive: He plans on reuniting his mother with a former flame, while she plans on forcing him to get over his phobia of commitment in relationships.

"I call this a different kind of love story, because it's not just funny -- it's touching," said Streisand, to which Rogen quipped, "It makes it seem really dirty when you describe it like that."

The Guilt Trip opens Christmas Day. Watch the video to see the comedian and the Oscar winner play a speed round of our pop-culture word association game.