Seth Rogen tried to get Barbra Streisand to smoke marijuana on the set of 'The Guilt Trip'.

The comic stars alongside the legendary singer and actress in the film - where she plays his mother, who goes on an epic road trip with his character - and he encouraged her to indulge in taking his favourite drug on set.

He said: ''I did try. She wouldn't do it, but she told me she smoked pot with Peter Sellers. That's, like, the greatest story of all time. Barbra's got good stories, I could sit there all day and think of a celebrity, like 'What's Marlon Brando like?' and she'd have a story. She met Elvis! And she got high with Peter Sellers.''

Seth, 30, also said he didn't change his language or behaviour around Barbra, and she didn't get upset.

He added to Nuts magazine: ''I didn't censor myself. I like to say gross s**t every once in a while and she wasn't fazed. She's known much dirtier people than me throughout her life. She's always fussing and touching my hair. She's like my real mother in a lot of ways. I could swat her away like she was my actual mother.''