Why Did I Let You Leave?

He'd never, ever wanted to let go. Not when the boy hid the fact of Draco succumbing to the sickness, not when the boy refused to remove the suppressor, not when the boy became a political nightmare, and not when the boy stood up for the marauders and Lily. Severus had still been fond of him. Like a father would of his child.Too often he had stood passive when those who mattered to him left. He wouldn't now.