If there's one thing most Game of Thrones fans agree on, it's that Cersei Lannister (Lena Headey) is not long for this world, and in Sunday's episode, "Eastwatch," she may have mistakenly made a move that could prove to be her downfall: she revealed she was pregnant.

After Jaime (Nikolaj Coster-Waldau) seemed to have given up on winning the war against Daenerys (Emilia Clarke) following the battle against the Dothraki and Drogon in last week's "The Spoils of War," he secretly met with Tyrion (Peter Dinklage) in the bowels of the Red Keep to discuss the existence of White Walkers and a possible truce. Of course, Cersei later revealed to him she not only knew about his clandestine meeting with the person she still believed had killed Joffrey (Jaime quickly put her straight regarding Olenna's involvement), but she also threatened him and told him not to betray her again. And naturally, in the middle of all of this, she also revealed she was pregnant with their fourth child. What a convenient time to drop that bit of news!

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But was Cersei telling Jaime the truth?

We know they've had sex this season, so a pregnancy is entirely possible, but we're still not sold on the queen's bold claim. It really boils down to the fact that Jaime, who has literally been by her side since before they were even born, has slowly been pulling away from Cersei since the Season 6 finale. It's taken him much longer than most people to see the monster within his sister, but since she used Wildfire to blow up the Sept of Baelor and then allied herself with Euron Greyjoy (Pilou Asbæk) earlier this season, Jaime has been a little more hesitant to stand by his lover's side without question.

But then we must ask: why would she lie about the pregnancy?

Well, Cersei likely realizes Jaime is pulling away from her — she's anything but blind to what's happening around her — and it's possible that she realizes another pregnancy, especially after the deaths of their three children, might be her only means of keeping Jaime by her side in the coming months. It wouldn't be the first time a woman on television has lied about a pregnancy to trap a man. And with Cersei's promise that she will tell the people of the Seven Kingdoms that Jaime is the father — something most of the population would likely suspect but never be able to confirm — is something that's too much for Jaime to simply pass up. After all, he's never had the opportunity to publicly be a father. This could be his chance!

Lena Headey and Nikolaj Coster-Waldau, <em>Game of Thrones</em>Lena Headey and Nikolaj Coster-Waldau, Game of Thrones


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But if Cersei isn't telling the truth and Jaime discovers the deception, it's also possible that this ruse is the straw that breaks the hunky twin's back. There are many popular fan theories out there about Jaime ultimately being Cersei's downfall — and just as many foreboding hints that she might be his. The revelation that she lied about her pregnancy could easily push a man who's already unsure of his allegiances to the brink.

Of course, there's also more to it than that. In one of the show's few flashbacks, an old gypsy woman a witch tells Cersei a number of things about her life, including that she will bear three children, all of whom will die. It's a prophecy lifted straight from George R.R. Martin's novels. But there is a part of the prophecy that was left out of the television series. It says, "And when your tears have drowned you, the valonqar shall wrap his hands about your pale white throat and choke the life from you."

Valonqar translates to "little brother" in High Valyrian; Cersei has always assumed that Tyrion is the little brother the prophecy is referring to, which is why she has spent her entire life attempting to be rid of him. But Jaime was also born after Cersei, which makes him her little brother, too. Is it possible that Jaime, upon realizing that Cersei has lied to him about a possible fourth child — remember, the prophecy states she will only bear three children — might strangle her in a fit of rage? Maybe. Maybe not. Only time will tell now. But we're positive this latest revelation won't end well for the queen.

Game of Thrones airs Sunday at 9/8c on HBO.