Game Of Thrones Spoliers
Sean Bean may have revealed a massive "Game of Thrones" spoiler regarding Jon Snow's parents. HBO

Ask any "Game of Thrones" fan who has read George R.R. Martin's "A Song of Ice and Fire" books about the "R+L" theory and expect to hear a lengthy discussion about Jon Snow's parents. In what could be considered a massive "Game of Thrones" spoiler, Sean Bean, who played the dearly departed Ned Stark, seemingly confirmed the popular fan theory.

WARNING: Full "Game of Thrones" Season 5 spoilers ahead. The rumor could affect future "A Song of Ice and Fire" novels as well as the HBO series.

Bean, speaking to Vulture's Jennifer Vineyard, stated, "I'm obviously not Jon Snow's dad." With six words, Bean seemingly confirmed the fan theory that Jon Snow is the offspring of Prince Rhaegar Targaryen and Lyanna Stark, Ned's sister. This theory has been one of the most popular as it makes a lot of sense in terms of the "Game of Thrones" plot. Ned is honest to the point where he was beheaded for being a good man, so the idea of him having an affair during Robert's Rebellion, after only a few months of marriage to Catelyn Stark, does not make much sense.

Even if Ned had an affair, why is there so much mystery surrounding Jon Snow's parents? If Ned ran off with a wet nurse or Ashara Dayne, the younger sister of Ser Arthur Dayne who committed suicide after Robert's Rebellion and only mention in passing in Martin's series, why would he not just tell Jon Snow? With these unsatisfactory explanations, many fans turned to the R+L theory as it provides a good answer for the secrecy and it is also backed up by plenty of textual, albeit circumstantial, evidence.

Robert's Rebellion started when Rhaegar kidnapped Lyanna, who was set to wed Robert. Rhaegar held Lyanna at the Tower of Joy in Dorne, which was guarded by three members of the Kingsguard. Ned killed the trio, but Lyanna was already dying, in a scene which resembles her giving birth. She forced Ned to keep a promise, and their final words remained a secret. While Robert and Ned viewed the act as kidnapping some believe Rhaegar and Lyanna were in love.

In "A Clash of Kings," Daenerys enters the House of Undying and has a vision which many proponents point to as evidence for the R+L=J theory. In Dany's vision, Rhaegar is seen with Aegon, who was believed to be killed during Robert's Rebelion, saying there must be a third child. Aegon and Rhaegar's daughter, Rhaenys, were killed by the Mountain, Ser Gregor Clegane. Dany is in possession of three dragons so it makes sense she is one of the "three heads" of the dragon, and Aegon, hidden away by Varys and Illyrio, appears in "A Dance With Dragons." Jon Snow, who also fits with another part of Dany's vision as the blue rose on the Wall, could be the third head of the dragon.

Ned took his final promise to Lyanna to the grave but a flashback, be it in "Game of Thrones" Season 5 or a future season, could easily solve that problem. Of course, Bean could be having some fun with "Game of Thrones" fans eager for any news, much like Lena Heady may have been doing with Lady Stoneheart.

You can view a video explaining the R+L=J theory, courtesy of Alt Shift X, below.