"Are you a boy or a girl?" "I'm an angel."

“I do believe that I’m in this state because you called me your husband,” he replied with a tight smile. That wasn’t what Crowley expected. She backed off, slightly. One hand hovered above Aziraphale’s thigh, light caught on the golden ring. “Do you… not want to be married anymore?” Crowley questioned in a soft voice. A horrified look crossed Aziraphale’s face. “Good heavens! No, my dear, never that, I promise you,” he grabbed her hand tightly and pressed it to his chest. “No, it is the… connotations, of the phrase, I suppose.” Crowley squeezed back. “Aziraphale, I know you’re upset right now,” she said in a strained voice, “but I would really appreciate it if you spell it out for me.” The angel let out a breath. He nodded slowly. “The thing that upset me, about your comments, was,” he said, “the gender, of it.”Or, how Aziraphale realises they're agender.