It’s such a shame when people treat the Jaime x Cersei incest as merely a plot device that GRRM uses as a shock factor or to kick off Bran’s arc. It’s nasty, yes, but also essential in depicting where the twins were psychologically at the beginning of the story, and its way of portraying their views on their genders is nuanced in a way we rarely see in mainstream media.

Both Cersei and Jaime are trapped by their gender expectations in different ways, which is why GRRM specifies so heavily that they are identical twins: they act as mirrors to one another.

“My brother, who is me, only born fortunate.”

Cersei’s inner resentment towards Jaime and her need to control him stems from her frustration at the confines of her gender. She has the ambition to achieve greatness; she craves respect, drive, recognition; she’s every bit her father’s daughter. But instead she’s wedded off to a wretched man who SAs her as he moans the name of a dead woman. She’s forced to watch Jaime, a man who wears her face, be fed every opportunity that she’d kill for… and he wastes it. Jaime is not bloodthirsty, he isn’t particularly ambitious, he isn’t strategic. He’s spoiled with luck, wandering through life as the Lannister heir, who dotes on the dwarf that killed her mother, who cruises on his innate talent as a genius swordsman and doesn't even begin to comprehend how good he has it. He’s done nothing to deserve it, while she must fight tooth and nail to get even an ounce of the acknowledgement that he’s born into. She schemes, and she weaponizes her appearance, because those are her scarce assets. Cersei does not see Jaime as her brother; he isn’t a separate entity from herself. Jaime is her male reflection, a tangible ghost of everything she could have had.

“My sister, who is my maiden, therefore I am her knight.”

Jaime’s born into a world of expectations he has no interest in bearing. He is a boy, he will be a man, he is meant to be a protector. But he’s failed at protecting every single thing he loves. He had to stand uselessly by the door while he listened to the king abuse his sister, he was the reason his brother lost his one chance at true love, he watched all of his children die in front of him. The one time he did his duty as a knight and slew the evil which killed innocents, he was condemned for it and stripped of his honour. So Jaime learned young that everything is a joke… what is it to be a man? The role he was taught was a lie: true valour is punished. And in practice, what is a man other than one to sling cock at unwilling women? So he doesn't take anything seriously, because the game is unplayable. And he doesn’t pray to the gods, because where were they all those times he desperately begged? Instead, he looks to Cersei: his female mirror. As long as she remains his Maiden, he can be her Knight. Only attached to her can he find meaning for himself, and removed from her, he becomes just Jaime once more. And Jaime is not a pleasant thing to be.

Their relationship is so toxic that the literal fucking is actually a small part of it. Neither of them views the other as a complete entity, but rather as a tool for themselves to project their own experiences of inferiority and disillusionment onto. The emotional incest outweighs the physical incest; that's how messed up these two are. The only good thing Tywin gave his children was the face card.

the reason I am now going to be shoving TMK in ur face forever is that 1) it’s a GRRM-approved script that goes out of its way to show Jaime did it for the right reasons and was in fact the only (male) moral actor in the fucking red keep throughout the Rebellion and 2) the POV trap does not apply here. it cannot apply. we are no more in Jaime’s head than we are anyone else’s in any given scene, and so if the playwright needed to indicate that Jaime killed Aerys for Tywin, or for his own skin, he would’ve had to find SOME way of externalising that thought process.

except he doesn’t. Jaime tells Aerys himself there are 500k ppl in the city when Aerys reveals his wildfire plot, and he personally tells Aerys not to let Tywin into the city, bc he knows Tywin would sack it. Jaime actually stands to benefit from Tywin entering KL! but his advice in both the books and the play is not to fucking let him in lol. we also have jaime being physically threatened multiple times by the KG for even voicing dissent, so if they wanted to indicate Jaime’s supposed self-interest then having him repeatedly put his life on the line just to SAY something is. not a great way to do that