Or Regulus could think he'd gone mad. Severus hadn't quite anticipated that one, either, but he supposed it stood to reason. He found himself sniggering before he could help it, and shaking his head.
"Well, I won't deny being some Death Eater berk," he finally said, his tone still more than a little amused. "But I've absolutely no interest in hearing your confession, or sealing your execution, for that matter. Whatever you've done to betray him, Regulus ... I'm glad that you did it, and I'm glad that you're still alive." He gave a slight shrug, before adding, "The rest is unimportant."