Why Joaquin Phoenix and Rooney Mara won’t get married

They’re on the same wavelength! Dating since January 2017, Joaquin Phoenix and Rooney Mara “are so in love,” a source tells Us Weekly in the new issue. But that doesn’t mean the pair — who met on the set of Mary Magdalene and also star together in upcoming comedy Don’t Worry, He Won’t Get Far on Foot — have plans to walk down the aisle any time soon.

“They’re never going to get married because they think marriage is too mainstream,” reveals the source, adding that Mara, 33, has fully embraced her man’s unique way of life. “Joaquin transforms all his girlfriends into being holistic, vegan, spiritual and into saving the world,” the insider explains.

In April, the three-time Oscar nominee, 43, told Collider that he, his late brother River and his sisters Rain and Liberty (younger sister Summer had not yet been born) all decided to go vegan after a childhood fishing trip. “I just had a profound strong reaction,” to the fish being killed, he said. “I think that during that moment we knew that we were not going to eat meat anymore.”

Mara is also an animal-lover: “She was recently trying to find a holistic doctor for her dog,” says the source.

In September, Phoenix told The New York Times that he and Mara were living together in Hollywood. “They don’t really like to go out,” notes the source. “They mainly just like to be with each other as the two of them. They’re in their own bubble.”

For more on Phoenix and Mara’s romance, pick up the new issue of Us Weekly, on newsstands now.