Sean Bean
Cast member Sean Bean of the new drama series "Legends" participates in a panel during Turner Networks portion of the 2014 Television Critics Association Cable Summer Press Tour in Beverly Hills, California July 10, 2014. Reuters/Kevork Djansezian

The “Game of Thrones” theory about Jon Snow’s mother has just been partially confirmed by Sean Bean. The 55-year-old English actor, who played Eddard “Ned” Stark in the HBO series, has just revealed a major spoiler from the George R.R. Martin novel and series.

Warning: the following contains spoilers. Don’t read further if you don’t want to know ahead.

There have been lingering theories about Jon Snow’s real parents online. A favourite fan theory, called “R+L=J,” has been explained in a video by YouTube user Alt Shift X.

Read: ‘Game of Thrones’ Theory on the Identity of Jon Snow’s Mother Explained [VIDEO]

The R+L=J theory states that Jon Snow, played by Kit Harrington in the critically acclaimed series, is the son of Ned’s sister Lyanna Stark and Rhaegar Targaryen. Ned only claimed Jon as his own as a promise to his dying sister.

By hiding Jon’s real identity as a half-Targaryen, he would be safe from Robert Baratheon, who has ordered the slaughter of all Targaryens.

The theory is a plausible one, made more so believable by the facts presented in Alt Shift X’s video, explaining Martin left clues on Jon’s real parents.

Martin keeps that one a secret even from show creators David Benioff and Dan Weiss.

And yes, even Harrington himself knows nothing.

But apparently, Ned, or rather Bean, does.

In an interview with Vulture, he discussed Ned’s possible return via Bran’s flashbacks in the fifth season of the show, which he is only willing to do.

“I’ve definitely got some unfinished business that needs to be resolved there. I’m obviously not Jon Snow’s dad. And you need that to be revealed at some point, don’t you?” he said.

But Ned not being Jon’s dad is not obvious. Although there have been talks, Martin has never revealed Jon’s true parentage yet. As far as the “A Song of Ice and Fire” readers and “Game of Thrones” fans are concerned, Ned is Jon’s dad. The only question is who his mother is.

As it happened, though, even his father’s identity is not who has been established from the start.

Bean continued, “So Bran would kind of be the one having the flashback, and he would see Ned praying, right? And revealing those things? You never know what those guys are going to do with that. It’s got to be something special. But I’m into that. I certainly would be into that. Print that! Give them a nudge!” Bean laughed, referring to the show’s runners.

“Hopefully I’ll get a call soon.”

“Game of Thrones” will be back for a fifth season.

Watch the R+L=J theory: