He thought there would be more time.
Once they got out - both of them, it didn’t matter how - he thought he had all the time in the world. The time to save it, again. The time for them all to decide what they wanted to do with their lives, with the wide open road ahead of them.
He should have said it then, when they were in the car and Sammy was passed out in the back and Cas was right there. When he reached his hand over and grasped Cas’s hand, laced their fingers together and thought to himself that this was home. He should have said it.
He should have said it when they were fighting back to back and they were just barely keeping up, just barely surviving. When the battle was finally over and they were breathing heavy and then they were groping at clothes and clashing teeth and tongue and lips together and he thought his heart might fly out of his chest. He should have said it.
He should have said it when they were in each other’s arms. When skin was pressed to skin and the scent of sweat hung in the air and he caught Cas’s moans with his mouth. When they were warm and sated and happy and Dean promised himself that he would never lose this, that he would never let go. He should have said it then.
He shouldn’t be saying it now. When he’s got Cas in his arms, but it’s not like last time. There’s too much blood, there’s coughing, there’s bright, sweet light leaking out of him. He shouldn’t be chanting it like a mantra, like saying it will somehow heal him, but he knows it won’t. He shouldn’t be sobbing it when Cas’s hand reaches for his face and fingers trace his skin and Dean feels the wetness of blood there and Cas smiles like it’s all gonna be just fine when he says,
"I love you too, Dean."