I am not Chinese, and although I've tried my best to research for this fic and other MDZS fics, there may still be errors that I was unaware of. If so, I apologize. If anything is offensive or incorrect, please let me know.

The title comes from the literal translation of 天子, which means "emperor" (as in Emperor's Smile) but is literally translated to "son of heaven" or "son of the skies." I found a twitter thread about it written by tothedeaths; the thread was more focused on Wei Wuxian and Wangxian, but I thought the interpretation worked equally well for Lan Xichen.

Lan Xichen is pouting. He'd probably get offended if Nie Mingjue said that and insist that he was frowning or maturely expressing his disappointment, but Nie Mingjue is the one looking at the face he's making, and it's definitely a pout.

"Mingjue-xiong," Lan Xichen scolds, "you know alcohol is forbidden in the Cloud Recesses."

"I'm pretty sure everyone who comes to Gusu tries Emperor's Smile at some point, Xichen," Nie Mingjue counters. "Including all of the students who come for the lectures."

Lan Xichen's pout intensifies. "It's forbidden!"

"Are you going to tell anyone about it?"

Lan Xichen hesitates, which is as good as an answer. If this were Lan Wangji, Nie Mingjue probably would be screwed; from what he's heard, Lan Wangji has made a reputation for himself of being a stickler for the rules, despite his youth. With Lan Xichen, though, Nie Mingjue thinks he's got a chance.

"I should tell my uncle," Lan Xichen finally says. "You know you're not supposed to have alcohol here. If you really wanted to try it, you could have visited Caiyi Town and had it there."

Nie Mingjue shrugs. "It's easier here."

"Mingjue-xiong-"

"The lectures are almost over anyway," Nie Mingjue adds. "I'll be returning to Qinghe in a few days. Is it really worth telling your uncle about now?"

The pout returns. This time, Nie Mingjue is fairly certain he knows why, and he can't really blame Lan Xichen for it. There's part of Nie Mingjue that's excited to go home, of course, but he will miss Lan Xichen, and he's fairly certain Lan Xichen will miss him too. That's the trouble with having his best friend be part of another sect. Nie Mingjue rarely gets the opportunity to leave Qinghe, seeing as he's the sect leader. And seeing as Lan Xichen is the Lan Sect heir and already somewhat of an acting sect leader in many ways, it's unlikely that he'll have much opportunity to leave Gusu. Once the lectures end, there's no way of knowing how long it'll be until they can see each other again.

Which is why Nie Mingjue wants to have a nice night tonight, and the first step towards securing that is making sure Lan Xichen doesn't tell his uncle about the Emperor's Smile.

"I won't tell my uncle about the alcohol," Lan Xichen suddenly decides, "but only if you promise to write to me after you leave."

Nie Mingjue makes a face. "Xichen, you know I hate writing letters. You've seen me try to write them to Huaisang."

"I know," Lan Xichen agrees, "but I want to keep up a correspondence with you, and we can't keep up much of one if it's just me writing to you and you never writing back. Anyway, would you rather write me letters or copy down all of the sect rules?"

Nie Mingjue sighs. "Letters, I suppose. Alright, fine."

Lan Xichen looks quietly delighted. "Good."

"Will you stay with me, at least for a while?" Nie Mingjue asks. "Sit with me. We can talk."

"You'll be drinking," Lan Xichen says, wrinkling his nose. "How much can we talk about while you're drunk?"

"I'm not planning on getting drunk," Nie Mingjue dismisses. "I've only got the one jar."

Lan Xichen looks at him curiously, then sits down at the table. "How much does it take to get drunk? Shufu always told me that if I drank, I would become inebriated and embarrass myself and my sect."

"Maybe you Lan have low alcohol tolerance, but in Qinghe, we know how to drink," Nie Mingjue replies. He pulls out a cup for himself, then hesitates before pulling out a second one. "Do you want to try it out?"

Lan Xichen starts. "What, drinking?"

"I won't let you do anything too embarrassing," Nie Mingjue promises. "Not in public, at least."

"It's against the sect rules!"

"So is having alcohol in the first place, so we're already breaking them."

"There's no reason for me to try that," Lan Xichen says in his best attempt at an imperious voice.

"What if you wanted to practice that technique you found in the library? The one where you burn out alcohol with your Golden Core?"

Lan Xichen blinks, and Nie Mingjue immediately knows he has him. Lan Xichen himself might not know yet, but Nie Mingjue can tell.

"I shouldn't," Lan Xichen demurs, but Nie Mingjue can see the curiosity in his eyes.

"It's a Lan technique, isn't it?" Nie Mingjue asks. "So it must be acceptable to your sect. Anyway, don't you want to learn something new during these lectures? Most of what we've learned so far has been things you already knew."

"Well…"

"You don't have to if you don't want to, but I won't tell your uncle if you won't."

Lan Xichen hesitates a moment longer, then smiles one of his more mischievous smiles. "Very well. For cultivation practice."

"Of course," Nie Mingjue agrees. "Do you remember what the text said?"

"It had a diagram," Lan Xichen remembers. "I think I remember it well enough to replicate it."

"Well, we've got a full jar for you to try with." Nie Mingjue pours two cups of Emperor's Smile, then pushes one over to Lan Xichen. "Shall we?"

Lan Xichen cautiously lifts his cup, then looks up at Nie Mingjue, apparently waiting for him to go first. Nie Mingjue downs his without hesitation, and after a moment, Lan Xichen does the same.

"Hmm," Nie Mingjue hums. "What do you think of the taste?"

Lan Xichen looks down at his cup. "How do I know if I burned it out?"

Nie Mingjue shrugs. "Do you feel drunk?"

Lan Xichen takes a moment to think about it. "I don't know how I feel," he admits, then his face brightens. "I'll play a song about it!"

Nie Mingjue blinks. "You'll what?"

"Where's Liebing?" Lan Xichen asks, beginning to search for his xiao. "Where could it be?"

"Xichen-"

"Do you know where Liebing is?"

"Wherever you last put it."

Lan Xichen laughs. "But I don't know where that is!"

"You're definitely drunk," Nie Mingjue mutters. "I guess you Lan do have a low alcohol tolerance."

"I found it!" Lan Xichen cries, pulling Liebing out of his sleeve. He lifts it to his lips and begins to play. His skills are unaffected by the alcohol, but if Nie Mingjue is recognizing the music correctly, he's pretty sure it's a rather bawdy Yunmeng song. Where Lan Xichen heard it, he has no idea, but it does sound nice on the xiao.

Lan Xichen is playing it very loudly, though, and Nie Mingjue doesn't like his chances if someone finds him with the very drunk sect heir and a jar of Emperor's Smile.

"Hey, Xichen, maybe you should stop playing," he suggests, hoping he doesn't sound too worried about it.

Lan Xichen slowly lowers Liebing, looking abruptly heartbroken. "You don't like it?"

"No!" Nie Mingjue assures him quickly, because that face is never one that Lan Xichen should wear. "I do like it, I like it a lot, but…" He wracks his mind for a reason that Lan Xichen should stop playing other than "someone will hear and then we'll both be in serious trouble," because he's honestly not sure how Lan Xichen will react to that right now.

"But I want to talk with you!" he blurts out. "And we can't talk while you're playing the xiao."

Lan Xichen's face brightens immediately, and he sets Liebing down on the floor with far less care than he usually handles the instrument. "Okay! What do you want to talk about?"

For a moment, Nie Mingjue considers using Lan Xichen's current state to ask him questions he normally wouldn't answer, then he shoves the thought aside and regrets that he even had it. He promised Lan Xichen that he wouldn't let him do anything too embarrassing, so he can't exactly ask him to embarrass himself.

"Tell me about your brother," he says instead, because that topic is enough to get Lan Xichen rambling even when he's sober.

Lan Xichen's face somehow manages to brighten even more. Nie Mingjue is pretty sure his face is just beaming out concentrated sunshine at this point. "My little Wangji! He wants me to call him that now, not didi. And he's started calling me xiongzhang instead of gege. I think he's cute when he's trying to be all grown up, but I could never tell him that, he would be so embarrassed! I love him so much. He's the best little brother ever." He pauses, then adds, "I'm sure your brother is a very good little brother too! And you might think he's the best. But I think Wangji is the best."

"I don't think Huaisang is the best," Nie Mingjue grumbles. "He's annoying and whiney and never practices his saber. He always just sits around painting his fans and playing with his birds."

"His fans are very pretty!" Lan Xichen compliments. "He's very good at painting."

"Don't tell him that, you'll only encourage him," Nie Mingjue says. "But if you really like his fans, I could ask him to make you one."

Lan Xichen's eyes go wide. "Make one for me?"

"If you want one. He makes enough of them anyway, I'm sure he can spare one for you."

Lan Xichen's face absolutely lights up. Nie Mingjue had thought he was beaming as much as a human being could possibly beam before, but apparently he'd been wrong, because Lan Xichen is managing to beam more now. "That would be amazing! It would be so nice to have one of your brother's fans! Can you write him a letter about it? Or should I write him a letter? But I haven't met him, so maybe it would be better if you wrote it. Or we could write it together!"

"Write it together?" Nie Mingjue repeats, not quite sure he understands.

Lan Xichen beams at him. "You're right, that's the best idea. We'll write it together. Do you have paper we can use?"

"You want to write it now?"

"Why not?"

"Because you're drunk."

Lan Xichen looks at him, surprised. "I am? But you're not, and you drank the same amount as I did!"

"I'm bigger than you, and I'm used to drinking."

Lan Xichen eyes him calculatingly. "You're not that much bigger," he declares. "Maybe a little bigger. But not huge."

"But I have drank before, and I've got more of a tolerance for it than you do," Nie Mingjue replies. "One cup isn't enough to make me drunk."

Lan Xichen picks up his cup and looks at it wonderingly. "It's so small! Just this much was enough to get me drunk? No wonder Shufu always told me not to drink alcohol. It's very dangerous."

"Only if you're stupid about it," Nie Mingjue replies. "It's not dangerous right now. You're a little drunk, but I'm here to keep an eye on you."

Lan Xichen's eyes go wide. "You're going to take care of me?"

That's not exactly what Nie Mingjue said, but nor is it wrong. "Yeah," he agrees. "I'll take care of you."

Lan Xichen gasps in delight. "Oh Mingjue-xiong, you're the best! You're my favorite!" He leans forward and says, very seriously, "You can call me Lan Huan if you want. Or A-Huan! That's what my mother used to call me."

The suggested intimacy is somewhat startling, especially because Nie Mingjue highly doubts Lan Xichen would offer it if he were sober. "I like calling you Xichen," he says, hoping Lan Xichen isn't upset or offended by it.

"Okay!" Lan Xichen agrees easily. "I like the name Xichen too. It's a nice name."

"It is," Nie Mingjue agrees, grateful for the easy acquiescence. And then, because this is the first time he's ever head Lan Xichen mention his mother, he asks, "Did your mother pick it or your father? Or did they pick it out together?"

"I don't know," Lan Xichen replies. "But I don't think they picked it out together, because the only time I ever saw them together was when Wangji was born."

That is… not what Nie Mingjue was expecting to hear. "You what?"

"My mother lived in her house," Lan Xichen explains. "And my father lives in his. My father is in seclusion, and my mother was not allowed to leave."

"Why wasn't she allowed to leave?" Nie Mingjue asks, now starting to get a bit concerned.

"She killed one of my father's teachers," Lan Xichen explains, somewhat mournfully.

"Why?"

"I don't know, I never asked. But she killed him, and then my father married her, and she was imprisoned while he went into seclusion. Wangji and I were allowed to visit her once every month until she died."

This is all news to Nie Mingjue, and he expects it's news the Lan sect wouldn't want spread beyond their walls. He doubts Lan Xichen would be explaining it at all if he weren't drunk. He knows he probably shouldn't ask any more about it, but he can't quite help himself.

"How old were you when she died?"

"Nine," Lan Xichen replies. He looks sadly at Nie Mingjue. "For a long time after she died, Wangji still knelt outside her door on the day we were supposed to visit, even though he knew she was gone. I guess he wasn't ready to let her go. I wasn't either, but I knew we had to. But Wangji was only six."

Nie Mingjue nods, understanding exactly what Lan Xichen means. His father died recently, and he can't imagine what he would have done if he'd lost him when he was younger. His mother died when he was born, but he doesn't remember her, so he doesn't think that counts. His father's second wife has always been a mother to him, after all, for almost as long as he can remember. But losing a beloved mother at six - or nine, for Lan Xichen - sounds awful.

"Do you ever get to spend time with your father?" Nie Mingjue asks. He's only heard rumors about Qingheng-Jun and his seclusion, at least until Lan Xichen just explained it to him. He doesn't know how encompassing a Lan sect seclusion is.

"Sometimes," Lan Xichen says. "But in some ways…" He looks warily towards the door, then back to Nie Mingjue. "Can I tell you a secret?"

"If you want to," Nie Mingjue agrees.

"Sometimes I almost feel like my uncle is more of a father than my father is," Lan Xichen whispers, leaning forward. "I know it's wrong, and that my father is my father and deserves my respect, but Shufu is the one who taught me as a child and was there for me, and my father never was." Lan Xichen frowns a little, then looks almost stunned by his own words and quickly pulls back. "I shouldn't have said any of that. I shouldn't feel it."

"I won't tell anyone," Nie Mingjue promises immediately. He knows why Lan Xichen feels torn; it's not very filial of him to say such things about his father, but then again, it doesn't seem like Qingheng-Jun has been much of a father to him.

"Thank you," Lan Xichen says, his face relaxing into a smile. "Weren't we going to write a letter for your brother?"

"You're drunk, remember?" Nie Mingjue asks. "I think we should wait until tomorrow to write it."

"Oh, right!" Lan Xichen nods. "What do you want to do, then?"

Ideally, Nie Mingjue would like to figure out a way to sober Lan Xichen up, but he's not quite sure how to do that. "Uh," he says, making it up somewhat as he goes along, "I think we should have tea."

Lan Xichen nods eagerly. "I like tea!"

"I know you do," Nie Mingjue says, amused. "Do you want more of the tea I brought from Qinghe?"

"The spicy tea?"

Nie Mingjue blinks. "It wasn't really spicy. I mean, it was a little spiced, but otherwise, it just wasn't a bland Gusu tea. No offense."

"None taken!" Lan Xichen chirps. "But it was spicy. Good spicy, but still spicy. If you have more, I'll drink it!"

"I'll make some, then," Nie Mingjue says, standing up.

"Can I help?" Lan Xichen asks. "I don't want you to have to do it yourself."

"I can do it myself," Nie Mingjue dismisses.

Lan Xichen's face threatens a pout.

"But you can help if you want to," Nie Mingjue adds.

Lan Xichen brightens up again immediately. "Okay!"

Nie Mingjue knows that Lan Xichen, drunk or not, is a powerful cultivator and perfectly capable of making tea. He's still not a huge fan of having him near boiling water, considering how he's acting right now, so he suggests, "Can you get everything ready while I heat the water?"

"I'll get everything ready!" Lan Xichen echoes.

Nie Mingjue starts boiling the water while Lan Xichen, humming to himself, gets out the teapot and cups. He's humming the same bawdy song he was playing on the xiao earlier, and Nie Mingjue can't help but ask.

"Where did you hear that song?"

"Hmm?" Lan Xichen looks up at him. "The song? I think it's from Yunmeng. I heard some of the Jiang Sect disciples singing it. I couldn't hear what the words are, but I like the tune. It's pretty!"

Nie Mingjue decides against telling Lan Xichen what the words are. "It's a nice tune. It sounded good on the xiao."

Lan Xichen's face lights up. "Should I play it on the xiao again?"

"It's getting late," Nie Mingjue says quickly. "You probably shouldn't."

"It's not nine o'clock yet," Lan Xichen protests. "No one will be sleeping."

"People might be meditating or relaxing, though," Nie Mingjue counters. "And it's almost nine."

"It is," Lan Xichen allows, nodding. "Mingjue-xiong, you're so clever! And so considerate."

It's more wanting to cover his own ass than anything else, but Nie Mingjue doesn't want to get into that right now. "The water is almost ready," he says instead. "Are you ready?"

"I'm ready!" Lan Xichen agrees.

Nie Mingjue pours the heated water into the teapot to steep, then he sits down and gestures for Lan Xichen to do the same. "It is almost nine," Lan Xichen muses. "Do you think I can sleep in here? I don't want to go back to my bed. I'll be lonely."

"Sure," Nie Mingjue agrees immediately. After agreeing, he wonders for a moment if this'll get him in trouble tomorrow, but honestly, he's more likely to get in trouble for getting Lan Xichen drunk if he tries to go back to his own bed like this. If Lan Xichen wakes at five the morning like he normally does, they might even be able to sneak him out without anyone noticing. Assuming, of course, Lan Xichen isn't still drunk in the morning.

Well, Nie Mingjue decides, if he is, that'll be a problem for the morning. For now, they'll have some tea, and then Lan Xichen will go to bed and fall asleep like clockwork like he always does the second the clock strikes nine. When he wakes, hopefully he'll be sober, and Nie Mingjue will be able to good-naturedly tease him about being such a lightweight, and no one else will have to know that they ever got drunk together.

And maybe, someday, Nie Mingjue can get Lan Xichen drunk again. Preferably outside of the Cloud Recesses, though.

After a few minutes, Lan Xichen pours the tea, grabbing the pot before Nie Mingjue can stop him. He pours for each of them, then sips from his cup. "This tea is spicy," he proclaims. "But good."

"So not only are you a lightweight, but your tastebuds are underdeveloped," Nie Mingjue murmurs to himself.

"What?"

"Nothing."

Lan Xichen has two cups of tea, then his spine straightens. "It's nine o'clock," he tells Nie Mingjue, because somehow, everyone in the Cloud Recesses seems to know that instinctually. "It's time for bed."

"I'll put away the tea," Nie Mingjue says. "You get to bed."

Lan Xichen nods, beaming. "Thank you, Mingjue-xiong! You're the best."

"Go to sleep," Nie Mingjue chides lightly. "It's your bedtime."

Lan Xichen shrugs out of all of his outer robes, draping the multitude of layers on the end of the bed, then he climbs in and falls asleep immediately. He forgot to take off his forehead ribbon, but Nie Mingjue knows better than to touch it. And he didn't take off his headpiece, but at least he's not wearing a one like he does for formal occasions, just a small one that doesn't seem to be held in place by too many pins. He'll be comfortable enough.

Nie Mingjue watches him for another moment, then he sighs and reaches for the jar of Emperor's Smile. He's only had one cup of it so far, and after dealing with a drunk Lan Xichen and keeping him from being discovered by the rest of the sect, he thinks he deserves the rest of the jar. Anyway, it's best to drink away the evidence. He'll find some way to hide the jar once it's empty, and no one will ever need to know about tonight's drunken escapades.

But if he can get Lan Xichen to visit the Unclean Realm, where there are no rules against drinking, Nie Mingjue definitely plans to do this again.