ya ever think about how the lannister sibs all have big secrets kept from each other, like huge life-altering experiences? jaime's is the most obvious, the most talked-about, with the full story of his kingslaying and everything he endured from aerys leading up to it. it's clear enough to me that brienne was the first he opened up to about that, including either sibling. they never asked, but unlike ned stark and the rest deriding him as kingslayer, their lack of curiosity is no offense in itself bc as tywin's other children they would never judge him for turning his cloak purely out of family loyalty. ned's assumption of jaime's motives is directly tied to his judgment of jaime, but it's the judgment that rankles jaime so. choosing your father's life over a king's is hardly the worst crime in itself. how can he explain all the other reasons without prompting when its not just about his crime but all his trauma too? is there any basis for that in his relationship with cersei, who always relied on him for comfort and consolation but seems less adept at providing the same to him? or even with tyrion, his only real male friend for years, but also his baby brother, the one he was meant to protect and take care of, who was only 10 at the time of the kingslaying? even to fully share all with tyrion years later, both adults, could be something of a role reversal, forever shattering tyrion's image of him as the strong invulnerable golden big brother by revealing his own broken inner child. jaime can't break out from those sibling roles and patterns, so neither can ever understand that part of him, never knowing the early life he had at court without either of them with him.

and tyrion, who trusted jaime more than anyone in the world before learning the truth about tysha, still could not confide in him freely even when all that trust was still intact. jaime must have heard some story of what tywin did to tysha to feel the need to confess his lie, but he def didn't hear it straight from tyrion bc imo there's no way he could still think confessing would help anything if he understood how scarred tyrion was by what he witnessed and esp not knowing that tywin ordered him to participate at the end. tyrion could reveal all that to bronn when they barely knew each other but not to his beloved brother, his first and best friend. how can the most abused child explain all his unknown abuse to the golden child, the big brother meant to protect him who couldn't always do so? how does he even begin to reveal the deepest trauma that happened to him when jaime wasn't in the room, esp when the story does start with jaime apparently trying to help him by fixing him up with tysha?

and then there's cersei and all her secrets. she always turned to jaime for consolation, or at least when he knew she needed it, but how many times did he not know? how personally could she confide in him as they grew older and their paths diverged? we know the first big secret was maggy the frog's prophecy, her first big scare, which came on the cusp of puberty, an experience she couldn't share with her twin bc he would prob just laugh and make a joke of it. in their first real scene together, in bran's pov, he mocks lysa's motherly fears and likens her to cersei. ("I think birthing does something to your minds. You are all mad." He laughed.) then he makes light of her marital discord, ("And whose fault is that, sweet sister?"), having no idea of the depth of pain she'd suffered from robert, beyond his infidelities. he later blames her for being robert's queen, not his, only thinking of how she managed to arrange his kg post, that power to forever tie him to her in secret, never grasping her lack of control in marriage, that "a queen is only a woman after all". in her pride it was hard to reveal all she'd suffered as a woman, but she also couldn't rely on jaime's response if he knew of her abuse, knowing he would kill robert and get himself killed too, only making her and their children's lives more precarious. she couldn't trust him to listen about securing the throne before dealing with robert or that as robert's victim it was her right to decide such matters, to choose his fate, not jaime's place to avenge her without her say-so first. all bc they were both too stuck in their idea of jaime as her sword, nothing more, with jaime determined to protect her and tyrion, always a bodyguard before he ever donned a white cloak.

something something tywin did his best to play his children off each other and the most effective thing he did to divide them was by setting jaime up as the golden child and family protector. the designated lannister sword only pointing at threats outside their house. a knight serving his family whose protection was always limited, who could never protect them from the person who first hurt cersei and tyrion and made them who they were at a distance from him, bc ofc he couldn't fight his own father, much less slay him with a sword.

something something maybe the reason that joff+marg+loras was a surer recipe for kingslayer stew than robert+cersei+jaime is all down to that tyrell lack of abusive structure. not that loras cared more about marg, was more willing to kill for her than jaime was to kill robert, but that there wasn't a chance of marg hiding her misery from him if/when her husband abused her in their shared household. it's not like he understood her to the point of mind-reading but when their previous royal marital household involved her bearding for his boyfriend then they prob had a pretty good basis of open communication. in that sense, the lannicest twins with all their sexual and physical intimacy still had less emotional intimacy than the tyrell queen and her kg brother.