If canon, Shiro and Keith are star-crossed lovers both in the literal and poetic sense. I love it.
Absolutely everything about Keith and Shiro says literal star-crossed lovers and I adore every second of it. Shiro getting abducted on Kerberos? Lauren outright says, “But he would have come out to space for Shiro, cause Shiro was his family.” (source). Keith and Shiro are shown dramatically falling away from each other and landing on opposite ends of a desolate planet? The episode of them desperately searching for each other is literally called Across the Universe, named after an iconic love song. Keith goes through his BOM trial ready to turn away from his team and his duty as a paladin–even his own father? The one thing that breaks his revolve and sends him running back is Shiro. Shiro, who is the literal manifestation of his greatest hopes and dreams, the person he “desperately wants to see.”
And after, when Shiro finds out Keith is galra–is part of the alien race that brutally tortured and tormented him for a year? He accepts him with open arms, looks at him bathed in light in absolute awe, like he’s something precious and beautiful rather than the monster everyone expected him to see. Pulls him into a warm hug. Cares to the point where Joaquim even says, “with Shiro, we have that history. But he loves Keith, so he sees the good in him.” (source). It’s the fact that Shiro took Keith to Kerberos in lieu of his blood relatives or anyone else. It’s the fact that Keith was the last person he wanted to see before takeoff. It’s the fact that Keith’s the one running back to him when he crashes back to Earth. It’s Ulaz telling Shiro, “The Blade of Marmora is with you,” and Keith’s blade being the thing that cuts him free.
It’s the fact that Keith loses Shiro again, fights the grieving process every step of the way. It’s grief-laden outbursts and begging for the Black Lion not take him. It’s talking to her like she’s him, shutting out the others to speak to the Lion like confession, trying to reach back out to Shiro through her. “I know this is what you wanted for me, Shiro. But I’m not you. I can’t lead them like you.” “Please, no.” “This one’s for you, Shiro.” It’s how Keith was the one to find “Shiro” again, it’s the fact that none of the others are there for the reunion and it’s just them. It’s always been them. Just the two of them, floating steadily into each other’s orbit as they gaze out longingly after one another across the vast expanse of space.
It’s how Keith is the only one “Shiro” can bear to let see him like this. So vulnerable and alone. Hiding the true depth of his trauma from everyone else, allowing just Keith to stay by his bedside and care for him after all this time. The quiet intimacy of the bedroom scene, the way that Shiro teases Keith for being his knight in shining armor again. “How many times are you gonna have to save me before this is over?” The way Keith smiles and simply says, so unabashed and unconditionally fond, “As many times as it takes.” As if it’s that easy, as if you can swear a life debt just like that. As if staying by Shiro’s side and keeping him safe was all he could ever want.
It’s the fact that Keith pulls apart from the team in the first place in part because of Shiro’s needs. It’s the way “Shiro” tells Keith he and the rest of the team will always be there for him. It’s the way Keith focuses solely on Shiro and says, “I know. And I can’t tell you how much that means to me.” Pulls him into another warm embrace that moves the others to tears. It’s because Keith skids to a halt in front of the Black Lion and panics. It’s the way he says Shiro’s name so forlornly, the way he screams, “Ilun, Vrek, we have to stop! Shiro is out there!” It’s the way he races back inside and starts disarming bombs while they’re still ticking, even as his own teammates turn away and say, “Then you’ll die with them.”
It’s the fact that they’re always torn apart only to come crashing back together. It’s both of them together even with the whole universe against them. After everything they’ve been put through, after all they’ve given…they deserve to be together.