Angelina Jolie and Brad Pitt's friends warned them against making 'By the Sea'.

The couple - who married in August, nine years after meeting on the set of 'Mr. and Mrs. Smith' - play a husband and wife struggling with their relationship in the forthcoming drama and their concerned pals were worried the material would spill over into everyday life.

Angelina - who is directing the film - said on the 'Today' show: ''We did a drama about a bad marriage

'''A lot of friends of ours thought is was a really ... they didn't say a bad idea ... but they asked us a few times if we were sure we wanted to do it.''

Earlier this week, Angelina admitted it had been ''uncomfortable'' working on the movie with her husband - with who she has children Maddox, 13, Pax, 10, Zahara, nine, Shiloh, eight, and six-year-old twins Knox and Vivienne - but felt the experience had made their marriage stronger.

She said: '''It [was] uncomfortable but we've already shot it, we've survived it and we're stronger for it.

''It was very tough material, so for any actors it was heavy dramatic emotional work.''

The movie is set during the 1970s and sees former dancer Vanessa and her writer husband Roland travel together. Though they seem to be growing apart, things change when they stay in a quiet seaside town and get close to some of the inhabitants.