Angelina Jolie admits making 'By the Sea' with Brad Pitt was "dangerous".

Brad Pitt and Angelina Jolie

Brad Pitt and Angelina Jolie

The 40-year-old beauty directed and starred in the drama with her husband, in which they played a rowing married couple, just weeks after they tied the knot in 2014 and she admits they agreed to work together in order to "test" their relationship - something she doesn't want to repeat in a hurry.

She said: "It was our way of testing ourselves. We knew that if we could get through this, we'd come out even stronger and happier. And we did.

"We've always liked putting ourselves through challenges, even though it was maybe a little more dangerous for us as a couple.

"I don't think we want to go through it again though."

Angelina - who raises kids Maddox, 14, Pax, 12, Zahara, 11, Shiloh, nine, and seven-year-old twins Knox and Vivienne with her husband - found the first week of filming particularly difficult, until she and Brad had a frank conversation.

She told Britain's OK! magazine: "The first week was the hardest because Brad knew I was worried and impatient.

"You don't want to drag your own personal issues into the process, but we had a talk and decided we were going to be completely honest with each other."