But it didn't work out quite as they had planned.
"There were a few days when we thought this wasn't the best idea," laughed Jolie, who wrote, directed, produced and co-starred with Pitt in the low-budget domestic drama. "There were days when we were really worried and it was hard. If we had married and were just starting a relationship it would have been a disaster but because we have been together so long we wanted to see how far we could push our relationship and our love and see if we can work together under very intense circumstances and with very complex issues and see if it would make us better.
"But at the end we came out of it thinking this was the best honeymoon because the film says, 'whatever you go through, weather the storm and stick together.'
"So it was kind of a message to each other that we are going weather whatever comes and we are going to stick together."
Inspired by the deliberately paced European art films of the '60s and 70s By the Sea tells the story of Jolie's Vanessa, a depressed former dancer and her heavy drinking novelist husband (Pitt) who arrive in a picturesque seaside town in 1970s France with their marriage in crisis. As they meet fellow travellers and local residents they begin to examine their problems and begin to come to terms with unresolved issues in their lives.
"I want people to walk away with different things from this film," said Jolie when we talked in the Four Seasons Hotel in Beverly Hills. "They will interpret it in a hundred different ways and it's intended to be like that. One of the things in our lives we all go through is grief and we all have to find a way to come through it. I think it's something people can relate to and maybe reflect on the moments in their own lives where they have had to overcome grief.
"I think it also says something about partnership and marriage and pulling through and that we have to hold tight together and work things out no matter how bad they get."