Jamie Dornan says some 'feverish' fans of '50 Shades' think he has a secret child with costar Dakota Johnson

• According to Jamie Dornan, the "50 Shades of Grey" fandom hasn't completely died down.
• He said one of the "mad theories" is that he and Dakota Johnson have a secret child together.

It's been over five years since the last film in the "Fifty Shades" trilogy was released, but according to Jamie Dornan, the series' fandom hasn't completely cooled off.

In an interview with The Guardian, Dornan, who played the BDSM-loving billionaire Christian Grey in the movies, said that there were still fans out there who believed he and his costar Dakota Johnson have a love child they're keeping hidden from the world.

"The fandom of that franchise is still feverish," Dornan said while discussing the critically panned but box-office-smashing trilogy of films launched in 2015 with "Fifty Shades of Grey."

Two sequels — "Fifty Shades Darker" and "Fifty Shades Freed," released in 2017 and 2018, respectively — have followed, receiving similar reception and commercial success.

Dornan said that some diehard fans still tout "all kinds of mad theories" online — and singled out one of the most ridiculous.

"Like that Dakota and I have a child together," he said. "I don't know who they think brings it up!"

The actor, who has three children with his wife, Amelia Warner, previously spoke to Variety about how he came to learn about the theory, saying that he received "a collage of photographs of a kid" in the mail during lockdown.

"I think they were trying to say that the kid was mine and Dakota Johnson's, and we'd had this baby while we made the first 'Fifty Shades' movie," Dornan said. "It piqued our interest, let's say. It was a bit freaky."

The actor also told The Guardian that at the height of the frenzy around "50 Shades," a tabloid published photos of his home, which meant he had to ramp up security.

"At one point, we had a stalking, getting-the-authorities involved situation," he said.

"I get all kinds of mad stuff, which if I'm honest I'm quite fearful of, so I stay away from it," he added.

Since "Fifty Shades Freed," the final movie in the series, the Northern Irish actor has appeared in Kenneth Branagh's Oscar-winning film "Belfast," Chris Sweeney's TV series "The Tourist," and other projects.