Tim Burton and Helena Bonham Carter laid down strict ground rules before filming SWEENEY TODD: THE DEMON BARBER OF FLEET STREET together - fearing the stress of the musical would wreck their relationship.
The pair enjoys a famously eccentric union - they own adjacent London houses that are joined by a door - and both feared spending an extended period in each other's company would drive them apart.
Bonham Carter reveals, "Being involved with people you work with is not a very good idea. To make it work, Tim and I had to lay down some commandments, set some rules.
"For me, it was a matter of learning to shut my mouth, because my initial instinct is to talk and talk. And he's not very forthcoming with compliments, so I needed a bit of reassurance here and there.
"And not talking about work at home, of course."