Jamie Dornan on Saying Goodbye to Christian Grey: 'It's Bittersweet' (Exclusive)

Plus, the actor's co-star, Dakota Johnson, reflects on the most 'difficult' part of filming the franchise.

As much as Jamie Dornan has loved playing Christian Grey, he's ready to say goodbye to the 50 Shades of Grey character that made him a household name.

ET caught up with the 35-year-old actor at Palais Garnier, a more than 150-year-old opera house in the heart of Paris, France, on Tuesday, where he opened up about what it was like playing the seductive entrepreneur one last time for the franchise's third installment, Fifty Shades Freed.

"It's tough in some respects, but it's also really nice and kind of bittersweet, I guess," he told ET's Cameron Mathison. "I think when you finish any movie or TV series or whatever, you've invested so much [time] into the character and the job itself and the other actors and the crew."

"That's sort of tenfold if it's a sequel or trilogy of films," he continued. "For the most part, we had the same crew back [and] obviously the same actors back, so you're that much more invested in these people and their lives and that much more closer to them. So, it makes it harder to say goodbye."

Dornan said that at the same time, he's thrilled to shift his focus to something new.

"Because you've been playing this character for a few years, whatever it's been, four and a half years, you're quite happy to say goodbye," he shared. "Because it's nice to put that aside and move on."

ET also spoke with his co-star, Dakota Johnson (who plays Christian's lover, Anastasia Steele) on Tuesday, where she echoed Dornan's sentiments.

"It feels, it doesn't feel tough. It feels pretty great," she exclaimed. "I'm so grateful and I'm so proud of these projects and I feel like we did it."

"It was really difficult and I feel, I feel proud of them [the movies]," she added. "I'm grateful that I had the opportunity and I'm really looking forward to my life, given the platform that it's given me. There's nothing negative about it."

Reflecting on her involvement with the franchise since the beginning, she said the toughest part of it all was "the subject matter."

"[It's] obviously a bit intense, so to have that coupled with the commercial massivity of the film was difficult to handle sometimes," Johnson explained. "And then to get through it and film one and return back and do it again... We shot the second and third [movies] back to back. That was like six months of filming these scenes that are physically and emotionally quite vulnerable. And then you have the judgment of essentially the whole world, so -- no, they don't hold back."

Fifty Shades Freed hits theaters Friday, Feb. 9. Watch the video below to hear more exclusive interviews from the cast of the romantic film!