"No," Draco said. Not childish, but optimistic, in his view. "Well, if it was childish, then I'm guilty too. I hoped you'd be able to do that, too."
Moreover, he understood all too well that being a killer didn't make you an adult. It could make you more jaded, disillusioned, twisted, darker; it gave you a different view of the world, certainly, but not necessarily a more mature one. At least, Draco didn't want to think of this as growing up. Eventually he would become a real adult, separately from the person he was now. That would be what he told himself, anyway.
He ran his fingers lightly through her hair, thinking, eyes closed. He knew what she was going through, didn't need (or particularly want) to see it in her eyes to understand. He did wonder if she felt, as he did, the thrill of victory, or whether that had been specific to his situation - but he wasn't going to ask.
"It'll pass," he said. "What you're feeling now, it'll go away." It hadn't for him, but that was because he'd been forced to continue using violence, to grow accustomed to it.