Once House started to move, Nathan brought up the rear, his attention for the most part behind him to bring up another barrier of fire between human and demon should the need arise. Though his attention was mostly on that, he couldn't help but chuckle at her retort. As much as he'd like to set the fake doctor straight himself, it was almost worth it to consider holding him down while Cordelia verbally flailed him alive. That would be pretty entertaining, after all.
Her announcement of Peter's text got a laugh out of him, surprisingly, given the topic. "Right. He's a fine one to talk," he said, rolling his eyes in a very exaggerated fashion, though it was all in good humor. He understood Peter's concern, and unlike times of particular hotheadness, fully recognized the reasonableness of the request, even if people could be healed or brought back from death. Not all could, after all. That good humor, however, faded as his gaze landed on House.
"I'd say it's a pleasure, but I'd be lying," he said to the man, waving the flamethrower in greeting. It wasn't meant to look friendly. "The pleasure would actually be in kicking your ass." The smile he delivered that line with one nothing short of the best one in his repertoire of politic smiles, notable because it was utterly and wholly fake.