Dean turned the paper over in his hand. In and of itself, it wasn't much. Just a piece of paper with a name on it. It wasn't necessary at Ridgeway, it didn't mean the same things it would mean back home. But it wasn't the paper that mattered.
Dean wasn't always the smartest guy around. He could be pretty dense about pretty big things. But the real meaning of the gesture of a new birth certificate for Aiden, bearing the name 'Winchester' was not lost on Dean.
Aiden was his son in all the ways that mattered. Dean had assumed some kind of parental role in Aiden's life even before he was born. He'd gone to Anna when she needed someone there, even when he knew he shouldn't have gone from Cas and Jo. He'd made sure she'd eaten, he'd sung to her and the baby. And he'd looked after Aiden, too, once he was born. He'd shown more interested in the boy than Crowley ever would.
After a moment of staring at the fancy print, Dean lifted his gaze and looked at Anna. Aiden was too young to understand any of it, and even if having Dean's name would benefit him in the future, Dean knew Anna hadn't done it for Aiden. She'd done it for him, because Aiden was his son.
He didn't trust himself to speak. He only nodded, and the expression on his face probably said more than words ever could. he was honored, thrilled, over joyed. He knew exactly what the gesture meant, and words- or at least the words he knew- we insufficient.