It wasn't sixteen, at least. Derek let out a breath he hadn't known he'd been holding, and relaxed, lying back against the floor.
"Four months ago," Derek said, softly. "You turned seventeen four months ago." Which was barely seventeen. He sighed, closing his eyes. Legally, he was in the clear, though. It was the auction house that had screwed up, but Stiles was hardly the first slave to be mis-aged. Ethically...that was another story.
"Do you know how old I am?" he asked, cracking on eye open.