LOS ANGELES — Barbra Streisand would really rather relax than star in a movie.
‘‘I like not to be bothered,’’ she said during a recent interview. ‘‘I like to look at the ocean and swim in my pool and play with my dog and see my son.’’
But for the director and writer of ‘‘The Guilt Trip,’’ in theaters Wednesday, Streisand was the only choice to play Joyce Brewster, a loving but meddling mom who sees the bonding opportunity of a lifetime when her only son, Andy (Seth Rogen), invites her on a cross-country road trip. Streisand declined the role for a year. Then her real-life son, Jason Gould, joined the chorus of voices urging her to do it, so the legendary 70-year-old entertainer made a few ‘‘requests’’ of producers.
Could they promise weekends off and no call times before 8:30 a.m.? Would they consider renting a warehouse closer to Streisand’s Malibu home rather than shooting on a proper sound stage?
‘‘I get a little carsick sometimes so I didn’t want to schlep to Paramount, which is an hour and a half to two hours that time of the morning,’’ Streisand said. ‘‘So if you rent a warehouse and built the sets — it’s ridiculous what I was asking.’’
Yet the filmmakers obliged her every demand, and in the end, Streisand and Rogen shared one of the most pleasant, fun, and creatively comfortable acting experiences they’ve ever had. The two approach work similarly, they said, and they really became like mother and son on set.
‘‘Aw, you were proud of your mommy?,’’ Streisand asked Rogen sweetly, laying her head on his shoulder playfully after he complimented her performance in the film.
Rogen, 30, said Streisand reminds him of his own mother.
‘‘I think there’s a whole generation of mothers who kind of model themselves off of Barbra. She’s the patient zero of Jewish mothers,’’ he said. ‘‘ A lot of people see the movie from all races and nationalities and they’re like, ‘Oh man, she reminds me so much of my mother,’ and I think it’s because, it’s probably because your mother is a fan of hers and acts like her.’’
Rogen and Streisand also bonded as filmmakers. As multi-hyphenates who work on both sides of the camera, they brought a broad understanding of the moviemaking process and resulting openness to their roles. For example, during one scene where Streisand’s character tries to eat a 4-pound steak to win a free meal, the actress in her didn’t want to do it, but the director in her knew she had to.
‘‘Because, as a filmmaker, I don’t care what the actress has to go through,’’ she said.
‘‘Some actors are like that,” Rogen said. ‘‘Ones who’ve made movies are like that.’’
That director’s sense of story and filmmaking also informed their improv scenes. Streisand said ad-libbing comes naturally to her — ‘‘not that I’ve had to use it before in something like ‘Prince of Tides.’ ’’
Though their characters may seem Jewish (like the actors that play them), both said they tried to make them more generic.
‘‘But then your natural instincts come out,’’ Streisand said.
‘‘And you go Jewish,’’ Rogen added with a laugh.
Streisand then reminded him, ‘‘There are a lot of very famous Jewish entertainers,’’ echoing every Jewish mother ever.
Though Streisand’s reputation as a legendary talent and reported diva precedes her, Rogen said he was impressed by the Oscar winner’s approach to her work and demeanor on set.
‘‘If anything, it showed me that I should maintain sanity,’’ he said. ‘‘There’s no excuse to be crazy. Because Barbra’s not crazy. She acts very reasonably and she can get away with a lot of [stuff] that she doesn’t pull. I’ve seen people with much less power than her get away with crazier [things] than she’s ever pulled. . . . She could go bonkers and she doesn’t do anything.’’