"The Hunger Games" star Jennifer Lawrence has an undeniable on-screen chemistry with her work husband Bradley Cooper, so it comes as no surprise that they have been teamed up time and again in several movies already.

The two were a hit in "Silver Linings Playbook" back in 2012 and were reunited in 2013's "American Hustle." To continue their streak, Lawrence and Cooper's love team moved on to the 2014 flick "Serena," then finally to this year's "Joy," which is loosely based on the real life story of home shopping entrepreneur and inventor Joy Mangano.

Lawrence told ABC News that working with Cooper is so comfortable that she feels like she is simply working with her brother, and she credits director David O. Russell for taking their defenses down on one another.

"David made us a bizarre kind of form of siblings, in a way," the 25-year-old Lawrence said.

Cooper, who is 40 years old, cannot help but agree. He believes that after they filmed the awkward dance sequence in "Silver Linings Playbook," everything else they filmed seemed like a piece of cake.

"I feel very safe (with Lawrence)," said Cooper. "I can turn my brain off as an actor. I think, having to learn that dance routine (in 2012's 'Silver Linings Playbook'), we really didn't know each other at all. Talk about being vulnerable with somebody."

Their relationship even extends off the screen, and it seems like they always have each other's backs.

When Lawrence earlier spoke up against the startling gender pay gap in Hollywood, she naturally received tons of support from her fellow actresses such as Emma Watson and Lena Dunham.

However, there were some who were quick to criticize her as a brat. Some actors chose to remain indifferent regarding the matter, such as "Avengers" star Jeremy Renner, who insist he is just an actor and therefore cannot do anything to remedy the situation.

But not Cooper. The star from "The Hangover" lauded Lawrence's bravery for tackling such a sensitive topic and even expressed willingness to champion gender equality and help fight sexism in Hollywood.

"There's a double standard in the whole world, yeah, for sure. This is just one aspect," Cooper told ET Canada. "Anytime there's a place where a voice can come out and be outspoken -- something Sienna (Miller) did, or Jennifer - that's great. I think it is making a difference."