"It's going to be a real nose blower," DeGraw joked of the song, which will appear at the end of the movie, when speaking to Billboard earlier this fall. They wrote the track, he explained, on a bus ride to Nashville. "It was an overnight drive on the bus and it all just kind of happened. It was awesome. It was magical."
Added Caillat in an upcoming announcement about the track, "My friend Gavin and I were on tour together this summer when I was approached to write a song for 'Safe Haven.' I had never written a song for a soundtrack so was thrilled to be asked."
The two musicians seem to constantly be working together, and DeGraw says he'd like to record with Caillat as often as possible. "I think we have a real Dolly Parton/Kenny Rogers thing going on for this generation. We have a really special chemistry and you can really hear it on this song."
Caillat and DeGraw will debut "We Both Know" on the Today Show on New Year's Day, Jan. 1, 2013, and the Dan Wilson-produced song will land on the film's soundtrack in February.
"We Both Know" hasn't been set for either artist's upcoming album yet, but both say they would like to see it on their respective future releases. Caillat just dropped an album, the holiday-themed "Christmas in the Sand" on Oct. 23, but DeGraw could be due for a new album soon, as his last release, "Sweeter," hit shelves in September of last year.
Caillat's "Christmas in the Sand" included five originals and 10 holiday standards, with guest appearances by Brad Paisley and DeGraw -- who joined Caillat on "Baby It's Cold Outside."