Michelle Williams was "incredible" to work with, co-star Ryan Gosling has revealed.
The duo, who star as married couple Cindy and Dean in Blue Valentine, have been keeping people guessing as to whether they are enjoying a romance off-screen.
Teasingly, Ryan talks about his co-star with great affection, saying: "I feel how Scottie Pippen might have felt in the Chicago Bulls heyday, when he would give the ball to Michael Jordan who would soar through the air and slam dunk it - that was what working with Michelle was like."
He added: "She gives an incredible performance and it's incredible to be there and watch it happening. I don't think I could have done the film without her."
It's hardly surprising he found it heart-wrenching to say goodbye.
"Letting go of the movie was the hardest part because it became such a big part of my life," he admitted.
"For five years, I lived with this character and this film, and I think both Michelle and I had a hard time taking off our wedding rings at the end. We had come to care so much about these characters, it was hard to let them go."
:: Blue Valentine is released on January 14.