Spanish actress Penelope Cruz (L) and Spanish actor Javier Bardem have replaced Angelina Jolie and Brad Pitt as the smouldering A-list couple on Cannes' red carpet
Hepburn and Tracey, Bogart and Bacall, Joel Coen and Frances McDormand: movie magic often has real-life love stories behind it, but star couples at Cannes say you must tread carefully when mixing work and romance.
Spanish Oscar winners Penelope Cruz and Javier Bardem, who have replaced Angelina Jolie and Brad Pitt as the smouldering A-list pair on Cannes' red carpet, have already teamed up on nine movies but said they were in no hurry to rush back to a film set together.
After the premiere of their new thriller, "Everybody Knows", which opened the festival, Cruz said dryly that while she enjoyed working with her husband, she wouldn't want to do it all the time.
"It's not something that we plan on doing every two years."
Cruz said she and Bardem, who have two children, were paid equally for the film and have strict ground rules about leaving the push-and-pull of their personal relationship far from the set.
"It would not make your life better, I think, if you used certain things from your private life (on a film). So the fact that we know each other and trust each other so much only helps," said Cruz.
- Shop talk, pillow talk -
China's Zhao Tao, who influential movie website IndieWire last week called "one of the greatest actresses in the world", has made a half dozen films with her spouse, director Jia Zhangke, including "Touch of Sin" and "Mountains May Depart".
Their latest is another Cannes contender, "Ash is Purest White".
She calls her husband "Director Jia" while shooting, just like the rest of the cast, keeping their shop talk and pillow talk sharply separate.
"When I come home and we get back to our own family we have nicknames for each other -- but that is something that just belongs to both of us privately," she said.
Zhao said their relationship had grown more "dynamic" and collaborative since they made their first picture together, "Platform", in 2000.
"Back then, if the director thought a scene was good, I tended to think 'Yeah, it's good enough'," she said.
"Now it's more of a dialogue about the characters -- how I want from a female perspective to make a character come alive. I think he's very responsive to my opinions and suggestions."
Jia, who won the Golden Lion top prize at Venice in 2006 for "Still Life", told AFP their sometimes hard-fought consensus covered even ostensibly trivial details like costumes.
He said their shared love of Quentin Tarantino's "Kill Bill" movies led the couple to occasionally borrow some of the eye-watering colours of its costumes.
They revived the look in "Ash is Purest White", whose first chapter set in the 2000s recalls Tarantino and the Hong Kong action movies that inspired him with their ultra-stylish violence.
"We were just on the same page," Jia said of his wife.
- 'Really terrifying' -
It's often a cinema passion project that brings lovers together in the first place, as with A.B. Shawky and the producer of his debut feature "Yomeddine", Dina Emam.
"We didn't start dating until maybe right before production," Emam told reporters in Cannes.
The film, set in an Egyptian leper colony using non-professional actors who were not able to read or write, proved to be more of a bonding experience than they bargained for.
The two survived a "really terrifying" shakedown by amateur security guards, Cairo's byzantine bureaucracy and the vagaries of crowdfunding a complex project that surprised everyone by getting into Cannes' vaunted competition.
"It was a gruelling shoot, I can't sugarcoat it," said Shawky, at 32 the youngest director in the Cannes competition.
Emam agreed: "There's no amount of planning that could have prevented the things that happened on this shoot -- I think maybe we were a little cursed."
But after their baptism of fire, Shawky and Emam decided they were ready to take the next step.
"As soon as we were done with the film we decided 'I think we've gone through the hardest thing we'll ever go through in our lives -- I think marriage will be a piece of cake'," she quipped.
Spanish actress Penelope Cruz (L) and Spanish actor Javier Bardem have replaced Angelina Jolie and Brad Pitt as the smouldering A-list couple on Cannes' red carpet.
Chinese actress Zhao Tao looks on as her husband director Jia Zhang-Ke (L) talks at Cannes about their latest fil "Ash is Purest White"
Producer Dina Emam (R) and Egyptian director A.B Shawky married after the cruelling shoot of their film "Yomeddine" set in an Egyptian leper colony