America Ferrera and Amber Tamblyn pose together at the Los Angeles screening of X/Y on July 12. Credit: David Livingston/Getty Images

Tibby and Carmen are still besties! More than nine years since the ultimate friendship film, The Sisterhood of the Traveling Pants, hit theaters, the stars of the smash success remain close pals. 

Blake Lively, America Ferrera, Alexis Bledel, and Amber Tamblyn all reunited at the 2012 weddings of both Lively and Tamblyn, and on Saturday, July 12, Tamblyn came out in support of Ferrera's new film X/Y at a screening in Los Angeles. 

The film is directed by Ferrera's husband Ryan Piers Williams, and Tamblyn told Us Weekly it was "America's ass" that first attracted her to the project. 

The Joan of Arcadia alum, 31, couldn't stop raving about her former costar, describing them to Us as "very good friends."

"She was one of three people to speak at my wedding. She's one of my best friends," Tamblyn said of Ferrera, adding that they go on double dates, "all the time—to an irritating point. I'm not sure who I'm closer with."

The average double date with Tamblyn and hubby David Cross

"Usually America and I going out first, eating and catching up and talking about extensionalism and philosophy, and where we are in our lives. And that usually lasts about 2 hours," Tamblyn revealed. "And then the dudes join up and they have been and then we talk about sports for 10 minutes. And then America and I go back to being in love with each other. They go off and do their own thing." 

The stars who portrayed Carmen and Tibby in the smash film adaptation aren't the only members of the sisterhood who have remained close. Tamblyn revealed that Lively was key in helping her pick out her vibrant wedding dress. 

"It was actually like a marigold dress and the design of it—my friend Blake Lively really helped me with," she said. "She was someone who was sort of instrumental in it, and I knew I didn't want a white dress and I always thought of kind of a bright jewel tone."