There wasn't a moment of bliss the following morning, with a moment of realisation where everything fell to pieces, no, Keith woke up with an ache in his chest. He woke feeling as though his lungs had stopped working and somehow sand and rocks had filled his chest cavity so that he would have no hope of moving or feeling ever again. When Keith woke up the next morning, he just knew. There was no moment of 'oh, Lance doesn't love me any more.' and he half wishes there was and he half wishes that he had never woken up at all, wishes he'd slipped into a coma and died in his sleep.
And Keith isn't sure whether it's the actual losing itself that hurts the most, or whether its how Lance has made it so clear as to how little he actually meant and now Keith is second guessing every moment they spent together, every moment he felt happy and in love and as if everything was right with the world. Wasn't Lance feeling that too?
Because it wasn't as though Keith had suddenly sprung it on him – you dumped me, and now I will never speak to you again. Which, okay, Keith maybe could have given himself some leeway and think that Lance didn't know what would happen. But he did, Keith has told him again and again, if it doesn't work this time then that's it, that's it done forever and they will never again share an interaction.
And so after all the years, after everything, he wasn't even worth that. Because Lance knew, and he did it anyway. He didn't care that he and Keith would most likely never speak again, he didn't care that Keith would be gone from his life, Keith wasn't worth that, why would he be?
And so yes, losing Lance cuts him and it cuts him until he's been sliced through, but knowing that all of those times he's felt so incredibly in love, so incredibly happy and like this could be forever, Lance hasn't felt that even if he said he did. Because now Keith is gone and Lance is okay with that, Lance made it happen. Lance doesn't want Keith any more, doesn't need him, doesn't want him around. Lance doesn't care if he and Keith never speak again.
Keith isn't quite sure what he'll do now, because it's been Keith and Lance for so long, even when it hasn't quite been, that he isn't sure how to just be Keith. Who is Keith without Lance? Keith doesn't even know so hell if anyone else does.
And so Keith doesn't have a most important person any more, the person he'll text in the middle of the night to tell him he's so incredibly in love with him, or if he doesn't, he thinks about it a thousand times over before deciding he'll be embarrassed in the morning. He doesn't have a person to get up for any more, no one to make him think, yes, I have to get up so I can see his beautiful face and make him laugh and kiss him and hold him. No, not any more.
And it's funny, really (not really), because all of the times (the one time) Keith thought this could really be it for us, I could really break up with you right now, he stopped and he didn't because Lance means more than that. They mean more than that and they are worth saving. To Keith they were. Lance was worth it and Keith wasn't and that's how it is, and half the time Keith thinks he'd be better off dead and he wonders vaguely if he didn't have Shiro if he would, and he thinks that he might.
Because he hurts and he hurts and he hurts until he's numb and he can't feel anything and then somehow, he hurts some more and there might be blood but there also might not be because the entire world is underwater, or maybe that's just Keith.
Because Lance is okay, Lance has Hunk and Pidge and Allura and Coran and who does Keith have? Shiro? A Shiro who isn't here, who might never be. And Keith doesn't deserve to be the leader of this team, Shiro does. They need Shiro back, and then when they do they won't need Keith any more.
Because Keith knows that it's always been him in too deep and it's always been him that's had to catch himself for fear of falling over the edge, but he'd thought that this time they'd fallen over together and that at last they were on the same page.
Keith half laughs because he did this to himself anyway. He could have left it, he should have left it because he was done, he was over it, over Lance. The only reason he did this was because he couldn't watch Lance with any body else again, not like before. Lance, with his stupid flirting with all of the aliens, just so desperate for someone to love him, as so not to be alone. So why wasn't Keith enough? Keith loved (loves) Lance more than anything in the entire universe, let alone the entirety of that stupid tiny planet they'd once known as Earth.
He wonders if Lance could have waited until they could go back home, waited until they went their separate ways and wouldn't have to see each other anyway, wonders if he could have put up with Keith for that long. Wonders if it would hurt less if they actually didn't have to see each other, but they do. Every day. And Keith can avoid and he can avoid and he can sit by himself and he can cry but there's only so long he can avoid Lance for, it is only a ship after all.
Keith doesn't have a most important person any more.
He wonders how long it has been since he was Lance's.