"His courtesy name is Wei Wuxian," Lan Wangji says, as his first order of business. Wei Ying won't prefer anyone but Lan Wangji himself to address him or refer to him by his birth name.¹ He continues, then, clasping his hands behind himself and looking directly at Crowley. "We met at the age of fifteen and did not marry until I was thirty-five."

¹This is probably true, but Lan Wangji is projecting a little bit. He's heard so many cruel men refer to his husband by birth name, as though he hasn't earned the dignity of the courtesy name that was given to him as recognition of his status and accomplishments, that he himself likes that name to come only from his own mouth.