Angelina Jolie considers it her "job" to love husband Brad Pitt.
The 'By The Sea' director and actress, who married her co-star in the film in August 2014 after 10 years together, admits they don't always see eye-to-eye, but believes "big fights" make their relationship stronger.
She said: "It strengthens a relationship if you can pass those big fights and those big things where you really come head-to-head.
"As much as we can argue and fight, and we all have our challenges, at the end I say, 'My job is to love him.' "
The Oscar winner, 40, thinks the 52-year-old heartthrob gets better with age and is looking forward to growing old with him.
She told PEOPLE magazine: "I'm more interested in his 50-year-old self than his 40 year-old-self.
"And then you look forward to even more years together.
"Brad and I are fortunate because we see the beauty in each other's changes."
The couple, who have six children, Maddox, 14, Pax, 11, Zahara, 10, Shiloh, nine, and seven-year-old twins Vivienne and Knox, play unhappily married spouses in their new film, but Angelina recently insisted it doesn't reflect their real relationship.
She said: "I'm counting on the audience to know that if it was close to us at all, we could never make this film. It's because we're actually very, very stable and these aren't our issues."