Even when he'd gone to visit Wei Ying in Yiling, and had met A-Yuan for the first time, it was... something nice. To be able to make him smile with a toy, fill up his belly with a good meal of absolutely no turnips: these were the things that had made him smile when they'd met, had carried him through some dark times in his life.

And so now, hearing that, even after all this time, he regards Wei Ying as family - not just in his gratefulness to him for saving his life, but as an older brother. Hopefully, maybe, as another parent.

Lan Wangji, who is most grateful himself, that his family has come to this hotel, that he has had the company of his brother, and his husband, and now his son, is moved to smile. It's a bare quirk up of his lips, but it might as well be sun shining through from behind clouds. "Very well," he answers.

It isn't really customary to get permission or blessing from one's children, but he feels better having received it. Like puzzle pieces clicking into place: right.