Kate Bishop and Castiel
Castiel remained silent for a moment, as he considered what Kate was saying. He never held it against Balthazar for being jealous of Dean Winchester. He understood why he would be. After all, confessing his love for Dean then dying for the man, well. It was a lot. "I also killed Balthazar back home. Our relationship has been a bit... eventful. I mean, it's good now..." As long as Castiel didn't cause Balthazar any more jealousy.
He laughed softly, "I'm not a vampire." His wings fluttered out of sight for a moment, before reappearing. As though trying to tell Kate something. "They're not part of a costume," he said, in reference to his wings.