to me anyway i feel like dean's earth-shattering love for sam is very clear and straightforward and loud while sam's is harder to parse (and this is for multiple reasons. the narrative frequently lingers on dean's internality while neglecting sam's, for one. for another i think sam fundamentally is a quiet lover.) but god, it is so hard for me to even think about the way sam loves his brother because i will start crying! i will! sam loves that boy! despite everything, he loves that boy so much. beyond all reason. sam adores him. he's not the same kid who looked at dean like he hung the moon, hasn't been for a long time, but i think he loves dean for who he is and who he becomes. he looks at dean with both the clear eyes of someone who loves fully in the present and the rose tinted glasses of someone obsessed with the past and he alternates between these, i think, between loving the dean that is and the dean that was.
and it's so beautiful to me, this great and consuming love of sam's, and so tragic, both because i personally think he deserves better but because dean doesn't see it. he is either prevented from seeing it by circumstances or his own horse blinders or both, every single time. he's so wounded by sam leaving for stanford that he doesn't see how it took less than 10 minutes of arguing and only one genuine plea from dean for sam to get in the car with him--at this point the hadn't even spoken in two years. he doesn't hear in 2x01 when sam, on the verge of tears over his body, says "you can't go now, man. we were just starting to be brothers again." in dark side of the moon, heaven only shows him the memories of sam that rip him apart. for the four months he's in hell, sam loses his entire goddamn mind without him. nearly drinks himself to death. tries both suicide by demon and suicide by lilith. begs and tries to sacrifice himself and bargains and shatters apart and oh, dean will never see it. he'll never see the way his absence flayed sam apart. in yellow fever he's so caught up in his monologue that he doesn't catch the way sam looks at him, all lovesick and fond and adoring and more than a little amused.
god. fuck! even in all of their breakups, it's sam who comes back!!! every time!! in scarecrow, sam comes back for him because he didn't answer his texts! in the end, sam lasts all of a few days before he calls dean again! in all the alternate universes, sam loves him still! djinn dream sam had no reason to go with dean to hunt the djinn but he does, he gets in the car with the brother he thinks is a thief and a lunatic and a piece of shit and says, i'm coming with you. when zachariah wipes their memories and they're not even brothers (not even! brothers!) sam wesson looks at dean and says hey, run away with me. we're meant for more than this. we should be together. it's sam! over and over! because sam loves dean, always has, despite everything.
in the season 4 finale, just before sam is about to go down a road he can't turn back from, he pulls out his phone and clicks that voicemail from dean. and it destroys me that he will never, ever know that that voicemail was supposed to be an apology. that dean didn't think he was a monster. not really. it destroys me that dean will never, ever know that sam didn't hear that apology, that sam went to kill lilith thinking dean hated him.
all that love. all that endless, insane love in sam's heart, reserved for dean and only dean. endless and terrible, tragic forgiveness. and god, dean insists over and over again that everyone leaves him. as if sam doesn't come back, over and over again.