The Dancing with the Stars vet, 24, plays a woman with a mysterious past who falls for Duhamel’s character, a widower with two young kids.
The film, which hits theaters on Valentine’s Day – of course! – is based on the 2010 bestseller by reigning romance author Nicholas Sparks.
A father of five who has been married 23 years to wife Cathy, Sparks opens up his home in New Bern, N.C., in this week’s PEOPLE – and also offers his personal take on making love last.
“A lot of people say marriage is 50-50,” he tells PEOPLE. “It isn’t. It’s really 100-100. You need both parties invested in the marriage because life is life. There are dawns and dusks and passing seasons. There are storms. You need to have a real solid commitment, not only to each other but to the very idea of being married to each other. I just married someone extraordinary.”
As for Duhamel, 40 – who recently told PEOPLE that his four-year anniversary gift to wife Fergie was “a little something that I can’t divulge” – he admits that a recent real-life love story had him in tears.
“I was looking at Love Story in 22 Pictures, he says. “Have you seen it? It’s online, 22 photos of this couple, this guy going off to war who lost his limbs. It’s pretty great.”