NieLan to me will always be a very quiet relationship. From the start they know they can’t have the other for themselves. They can write long letters and spar whenever possible and kiss and maybe sleep in the same bed and the things that come with it, but they’ll never be able to marry; better yet, they are expected to marry other people some day. I think their relationship is build on an unspoken promise to love each other in their hearts if not in each others arms. Which I think is their tragedy when things start to go awry; Nie Mingjue becomes more angry and unreasonable. He cannot stop this. He knew he was meant to take up the curse from the moment he was born. Lan Xichen doesn’t want to see it. Maybe he can’t see how bad it has gotten. Yet, maybe, in private, Nie Mingjue is so much softer to him than he is to other people (of course - Nie Mingjue would never allow himself to hurt his lover). Maybe Lan Xichen does see it, and he desperately wants to get his old lover back. It hurts him to see Nie Mingjue this way and it hurts how he cannot get along with his a-Yao. Maybe, in the dark, he desperately tries to kiss it better, knowing that their unspoken promise to love each other is both strained beyond repair and they both try to hold on to it more tightly than they ever did before. They so, so badly just want to go back to what they knew, and they both know in the depth of their hearts where they don’t dare tread that it’s never going to happen. Maybe, when Nie Mingjue dies, a terrible part of Lan Xichen is happy he won’t have to see his lover get even worse; that he gets to keep what was still left from the first time he ever fell in love. Maybe he’s happy it’s over, and Nie Mingjue can rest. Maybe he’s wracked with guilt over not being able to cure his lover. He keeps smiling through all of it
