Beautiful Like Birds (слэш)

"Stiles?" he asks, turning on the light, and Stiles looks at him- eyes wide, a flicker of utter devotion and heartbreaking joy passing his features before his whole face crumples and-
"Daddy?"
John has never seen his son like this, or maybe he has, when Claudia died, but it's different somehow, more, and terrifying because he has no idea why. He's closed half the distance between them before he even has time to think it through, but it doesn't matter because Stiles has bridged the rest and flung himself into John's arms.
He falls apart like that, holding onto John so tightly that it's hard to breathe, but he can't care about that right now because his son is sobbing and chanting "Daddy," desperately into his shoulder.
[Or, the one where Stiles goes back in time to save the world, and surprisingly, survives to tell the tale.]