Blaine doesn't know how Nico knows, but he doesn't insult his intelligence by denying it again -- whatever gave him away, it must've been good. "How'd you find out?" he asks, lips twisted into a tight frown as he sizes up Nico's injuries again. "And more importantly, when? I don't remember going at you that hard any time recently," he folds his arms over his chest, like that's going to help him look tougher somehow.