The thundercloud slides up against an icicle smile. "No, you need neither hear nor see me, nor even stand in my foyer, Rodolphus, if you don't like it. But do not invite calamity on those who have welcomed you for friendship's sake against all good sense and expect to be thanked and thought witty for it. A lecture is the least of what you invited with this piece of unspeakable folly, the greater piece of that invitation being an engraved one to the Aurors, if not the bloody Unspeakables!"
He leans forward, black eyes drilling into Rodolphus's until they find the trail back to his misunderstanding about which old friend of Lucius's it is exactly that Severus is related to, run occlumental fingers around it like ghostly fingers on a crystal glass, and make it softly, softly ring. "Do not," he says, so quietly that his voice would mist no mirrors, "assume you know my capacities, or my sacrifices, or my restraint." For just a moment, he lets Rodolphus see exactly how much he's hated Rabastan, who made a small and mean popinjay of the man whose mirror image, free of him, Severus can both like and respect, who made Narcissa so miserable he could do nothing for her, lets Rodolphus see how Severus's affection for him was the only thing that kept Rabastan from an untraceable death, for years, and, later, years again.
As quietly, he goes on, his wand still holstered and his hands aware of but far enough from it not to escalate matters in that way, "You know nothing of me but my heart, whose scaled side I have never shown you, Rodolphus, nor wished to. Never," his eyes narrow a nanometer, "yet."