He decides the best course of action will be to explain everything to Nie Huaisang before the matchmakers ever reach the Unclean Realm. Jiang Cheng is well aware that Nie Huaisang is smarter than he is at dealing with people and getting them to do what he wants, however much he may like to pretend otherwise. If he knows about this ahead of time perhaps he'll be able to handle in such a way that it just... is not an issue.
And so, that evening Jiang Cheng takes the time to sit and write a letter to his friend.
The letter is short and to the point:
"Huaisang, I mentioned when we last saw each other that my mother intends to see me married. I may have let her believe I'm a cutsleeve to get out of it. Unfortunately, she's now having matchmakers propose male cultivators for my consort. Anyway, one (more?) of them will be arriving at the Unclean Realm soon. Obviously, neither of us wants that, so just say no and that will be the end of it.
Jiang Wanyin"
He resolved to send the letter tomorrow, via pigeon most likely (Huaisang did love his birds). He waited for the ink to dry, put it aside, then went to bed.
And could not fall asleep. Jiang Cheng kept thinking about what he'd written, and the more he thought about it, the more the words he'd written didn't sit right with him.
Jiang Cheng got up, light a candle, and read his own words back.
"--may have let her believe I'm a cutsleeve--"
"Unfortunately--"
"Obviously, neither of us wants that, so just say no and that will be the end of it."
Short and to the point, so much so, that you could call it brusque. Dismissive or rude, even. Nie Huaisang was used to his blunt and often caustic way of speaking, he'd certainly never taken offense before, and yet...
Jiang Cheng thought back to long days and often nights spent together at the Cloud Recesses after Wei Wuxian had left. How close they had become. Certainly the intervening years, grief and war had put distance between them, but Nie Huaisang continued to be one of very few people he considered his friends.
He certainly didn't want him to get the impression that Jiang Cheng thought he wasn't worth marrying, because that wasn't true at all. Nie Huaisang was talented, funny, cultured and intelligent (even if he tried to hide it), he was beautiful too. Anyone that married him would be lucky to have him. If Jiang Cheng were inclined to marry a man, Nie Huaisang would be perfect.
No, this letter wouldn't do.
Jiang Cheng burned the paper over the candle's flame and resolved to write different, better letter in the morning.
The next morning Jiang Cheng gets up at dawn, like he does almost everyday, and starts the day training with Sandu in his private courtyard. It's closed on every side except the east, facing a small pond that connects with the larger lake by a canal. Briefly he thinks about all the times Nie Huaisang has said he would love to see Lotus Pier, and he thinks his friend would like this view.
After his own, he goes to supervise the clan disciples' training, and it's only after breakfast that he returns to his study. He kneels in front of his desk, and pulls out a blank piece of paper, and tries to think about what this new letter to Nie Huaisang should say.
He's barely managed to write a greeting, when he's interrupted by Wei Wuxian sauntering into his study with absolutely no notice.
"Good morning, Jiang Cheng!" Wei Wuxian explaims cheerily and much too enthusiastically. He sprawls on the other side of the table and rests his chin on his hand "I heard the most interesting thing this morning in the market!"
"And I'm sure it can wait till later," Jiang Cheng said, irritated at the interruption. This letter is difficult enough to write as it is.
"Hmmm... I don't know about that," Wei Wuxian replies, unfazed by Jiang Cheng's unfriendly tone. He leans across the table conspiratorially. "I heard the matchmakers were back yesterday with a brand new list!"
Jiang Cheng glares and does not reply.
"But that's not all," Wei Wuxian continues, glancing down at the paper in front of Jiang Cheng. The ink hasn't dried, and so Jiang Cheng hasn't covered it. Nie Huaisang's name is quite clearly visible. Wei Wuxian's grin widens. "I also heard that a small delegation of them left this morning for Qinghe, escorted by some of our best desciples."
Jiang Cheng resists the urge to cover up the letter. He tells himself it doesn't actually say anything yet.
"That's none of your fucking business!" he retorts, lifting his chin even as he feels his face flush. He tells himself it's anger.
"Don't be like that, Jiang Cheng! Can't I be happy that my shidi has finally found a suitable bride?"
Jiang Cheng's eyes widen involuntarily and his pulse races. Wei Wuxian can't know, can he? If he heard it in the market, it means everyone knows.
"That's why you're writing to Nie-xiong, isn't it?" Wei Wuxian grins relishing the moment. "He doesn't have any sisters, so which one of his cousins is it? I know some of them. Did he help you choose?"
Jiang Cheng scoffs and leans back, relieved that Wei Wuxian doesn't know the truth of the matter. It means it's not common knowledge.
"What the hell are you doing anyway, gossiping about me in the market?"
"I wouldn't have to gossip if anyone had bothered to tell me about it!"
"That's because there's nothing to tell!" He lies, hoping Wei Wuxian will, for once, let it go.
No such luck.
"It must be one of the Nie first cousins from the main line, right? After all, you're a clan leader and that's the closest thing to a sister," Wei Wuxian taps his finger on his lip thoughtfully and Jiang Cheng realizes that there's no hope of writing the letter to Huaisang today.
"Unless..." Wei Wuxian looks back at Jiang Cheng, eyes sparkling as if he's solved a puzzle. "There's that cousin on his mother's side, a couple of years younger than us! She's about as close as an actual human might get to that bullshit list of requirements of yours!" He grins slyly as he leans over the table. "And she's very pretty, looks a lot like Nie-xiong..."
"What does it matter if she looks like Huaisang?!" Jiang Cheng exclaims, alarmed, and immediately regrets his outburst. Wei Wuxian looks positively giddy.
"Oh, nothing, just that since she looks like Nie-xiong, you must think she's pretty."
"You--!" Jiang Cheng sputters.
"Come on, Jiang Cheng! I've heard you say Nie-xiong is pretty more than once when you're drunk!"
Jiang Cheng's eyes widen in alarm.
"What? When!" He does not remember saying any such thing.
"At the Cloud Recesses, of course, and a couple of times more recently too," Wei Wuxian informs him smugly. "And it's not like Nie-xiong hasn't heard it either, you told him so at least once that I remember."
"I... what?! When did I do that? Why would I do that?" Jiang Cheng is mortified.
"You were very drunk, it was was the night that Lan Zhan caught me bringing back Emperor's Smile," Wei Wuxian says matter of factly, as if that narrows it down. "Anyway, my point is he knows you think he's pretty, and he knows his cousin looks like him. And he knows your dumb list too! It is her, isn't it?"
Jiang Cheng panics, mortified and unable to come up with a retort . He rises to his feet and points at the door as Wei Wuxian laughs in amused delight.
"Get the fuck out! Can't you see I have work to do?!" he manages to yell. He can feel a vein throbbing in his temple.
Wei Wuxian makes a show of sighing and pouting, but he gets up and saunters to the door. "Fine fine! You can tell me all about what Nie-xiong said to get you so worked up over her later."
"Get out!!"
Jiang Cheng does not manage to write the letter that day.
He doesn't sleep that second night either. He keeps thinking about what Wei Wuxian so casually revealed this morning. He truly has no memory of ever admitting to Wei Wuxian that he thinks their friend is pretty... much less of saying it to Nie Huaisang himself. It's mortifying.
He doesn't really question having said it, however. After all, it is true, he's thought Nie Huaisang is beautiful since they met. It's just a matter of fact, and not something he'd ever actually say out loud while sober.
He tries to think back to those long ago nights drinking in the room he and Wei Wuxian shared at the Cloud Recesses with Nie Huaisang, but it's been so long ago. He does remember Nie Huaisang simply staying the night several times, and even waking up with him in his bed (fully clothed, of course, nothing happened, they're friends and he isn't a cutsleeve!), but he truly can't remember ever saying it.
He tries to imagine what Nie Huaisang's reaction might have been. Would he have blushed and looked away? Would he have laughed and said "You're drunk, Jiang-xiong, go to sleep!"? Might he have said he thinks Jiang Cheng is attractive too? Or maybe he would he maybe have been too drunk to remember? After all he's never brought it up since...
No, it's too much to hope for that only Wei Wuxian registered and remembered it. He's going to have to assume that Nie Huaisang is well aware of him making an ass of himself.
He really needs to write that letter.
"Huaisang
I hope you and your brother are well. It has been a long time since we spoke last, and I have a lot to tell you.
Soon, a delegation of matchmakers will arrive to propose a marriage between you and me. I understand this must come as a shock. Things here… got out of hand. I will explain when we see each other and you will no doubt get a laugh out of the story. In the mean time, know that while I think you are certainly worthy of marriage, this proposal is a due to an assumption that got out of hand. I value our friendship greatly and hope you don’t take offense. I’m sure Chifeng-zun will dismiss the proposal, and that is the best course."
"Jiang Cheng!" The voice rings out mere moments before Wei Wuxian himself appears in his study, and Jiang Cheng scrambles to cover the nearly finished letter with other papers.
"What do you want now?" he asks, exasperated. He can see the ink blotting.
"I just spoke to Shijie."
"How nice for you," Jiang Cheng replies sarcastically.
Wei Wuxian ignores his tone and perches on his desk. "I asked her if she knew about your betrothal, and she has no idea either!" he says, pointing an accusatory finger at Jiang Cheng's chest, who swats the finger away.
"This again?"
"It's one thing for you and Yu-furen to keep me in the dark, but Shijie too?" Wei Wuxian says, crossing his arms.
"First of all, get off my desk," Jiang Cheng tells him, annoyed, as he pushes him off his perch. "Second of all, Jiejie just got back from Meishan Yu last night. Third of all, there is nothing to tell."
"Nothing to tell?! You've finally found someone you want to marry! Because I know Yu-furen asked your opinion--"
"Wei Wuxian!" Jiang Cheng sighs, pinches the bridge of his nose. "There's nothing to tell because the Nies will say no..."
He trails off. He didn't mean to confirm anything.
"So it is one of Nie-xiong's cousins!" Wei Wuxian exclaims triumphantly, before turning a quizzical eye on Jiang Cheng. "Why do you think they'll say no?"
"Get out. I have work to do."
"Is this why you're being so weird about this? You really think they'll say no? Why would would any family say no to a marriage with Sandu Shengshou, one of the great heroes of the Sunshot Campaign?' Wei Wuxian actually sounds earnest about this. It makes it worse.
"They just will! I know they will!" He replies, raising his voice.
"Come on, you know Nie-xiong wouldn't suggest you propose to someone who would say no..."
Jiang Cheng can only glare at this.
"...unless he didn't suggest her? Is this why you're writing to him?" Wei Wuxian leans forward and tries to grab the papers in front of Jiang Cheng.
"Out!" Jiang Cheng springs to his feet, slamming his fist on the papers before the other can reach them.
Wei Wuxian takes a step back, raising his hands as if to appease him. "Fine fine! But I really think you're wrong about this..." he says as he backs out of Jiang Cheng's study.
Once he's gone, Jiang Cheng sinks back to his knees with a huff.he waits a few moments before gingerly lifting the papers off his letter to Nie Huaisang.
It's mostly legible, but smudged and ruined. He can't send Huaisang this.
While he burns it over a candle, Jiang Cheng thinks maybe it's for the best. After all, Wei Wuxian almost read it. Any letter he writes might fall into hands other than Nie Huaisang's. It's probably a good idea to be more circumspect about what he writes.
What will Jiang Cheng finally write? I already know, and it will be on the published chapter 2 of the fic, which will be in the next couple of days 
#sangcheng #MDZS Continuing from this
He doesn’t remember ever actually saying yes, but he is well aware he never actually said no.
He blames it, in part, on being overwhelmed in the moment by the whole thing. Nie Huaisang, his friend, was considered someone who might potentially be a man’s consort? Was considered someone who would be his consort? The matchmaker thought they would be good together? To say the idea came as something of a revelation was an understatement.
Before his brain had quite caught up, the old matchmaker was talking about initial overtures, how to handle this admittedly unusual case. How to approach Chifeng-zun with the idea. And at that point, Jiang Cheng thinks, surely Nie Mingjue will reject this out of hand, right? But in the meantime, he can enjoy a little peace and quiet before having to sort out this mess.
He can always explain to Nie Huaisang. They’re friends, after all. He’ll probably find it funny. They can have a laugh over it the next time they see each other.