Lan Wangji knew he was a possessive man.
It has taken many years for him to accept this about himself and it had taken his marriage to Wei Ying to fully be comfortable with this fact. As a young man, he feared what his possessive nature would drive him to; feared his desires turning him from the right path like resentful energy corrupts a dead animal or plant into a yao or a steep hill encouraged a mudslide.
It took losing Wei Ying – first to exile from the wider cultivation world, then to death – for him to realize that just because he was possessive by nature did not mean he was without the will to control his actions. His wants did not become his deeds. He was not his father, who saw things he wanted and took them until he destroyed them.
He loves Wei Ying with passion and ardor but would never want to seriously possess him forever. He would never want to lock him away like a prized bird, to be seen and touched but never free; never want to forbid him from teaching, from traveling, from having friends and other people in his life; never want to shackle him to Cloud Recesses and loose the key.
It was a comfort to know that he could hold Wei Ying close and pant such hideous wants into his neck and hear Wei Ying play along with them – either protesting verbally while his body urged Lan Wangji on or agreeing so energetically it passed into the realm of absurdity and fantasy. It was a comfort to know that Wei Ying loved being marked up, loved it when their lovemaking left visible evidence behind for him to have as a reminder he could carry into meetings and classes, even if no one but him saw them. It was freeing to know that Wei Ying, when he left for night hunts or longer travels while Lan Wangji wrapped up any remaining duties he had before joining him, often referred to Lan Wangji as his husband openly.
All of this is to say, he understands why under most circumstances, the current situation he was in would be...uncomfortable. Under different circumstances, a student of Wei Ying's coming to challenge him for Wei Ying's hand and declaring that they had a “long standing and everlasting love” for his husband would be most upsetting.
As it was, the student in question was maybe all of five years old and had mispronounced “everlasting” in his declaration. He was also pointing a short stick at Lan Wangji in lieu of a sword (though, upon looking at it more closely, perhaps it was more of a medium stick, since it seemed to be almost as long as the boy's arm) and he had been led here by Wei Ying himself.
Wei Ying, who was looking down at the boy with such open affection that it was like looking back in time, when it was another little boy holding Wei Ying's hand. Lan Wangji himself wasn't immune to the charm of the small child, who was puffed up in offense as he near shouted his challenge and his little face scrunched up in a scowl that looked remarkably like Lan Yuan's did when he was much younger and had to stay inside during winter, even though all his friends got to play outside in a snow covered training field.
He's not sure what to do in this situation, if he's being honest. Playing along seemed like the obvious choice but he remembers being very small and very serious once. He thinks he would have preferred being taken more seriously as a child, at least for the things that actually mattered. But how seriously was he to take this? Obviously, he wouldn't be dueling a child but he equally didn't want to dismiss the young boy with a standard challenges are only accepted between equals as that would undoubtedly hurt the boy's feelings and possibly his self esteem.
Perhaps a middle approach?
“I can see you are very serious about this, Lan Bin.” Lan Wangji says and makes the decision to remain standing, rather than try to get on the boy's level. “I am sorry to have given you reason to think my husband is unhappy with me.” He continues.
The stick being pointed at him wobbles as Lan Bin's arm strains to keep it aloft.
“Teacher Wei is always happy and he likes cats and music.” Lan Bin says in response and Lan Wangji has never been more thankful for the way he was born than right now, because he knows his face isn't showing any bit of the heartwarming fondness he feels from that declaration.
“He does like cats and music, very much so. He also enjoys the color red.” Lan Wangji says and Lan Bin's whole face lights up.
“He showed us a red frog last class! It was so big and not at all smelly or slimy and it had little eyes!” Lan Bin says loudly while waving the stick around. Wei Ying laughs as he reaches out to take the stick from his student, quickly reaching out to bop Lan Bin's nose with a finger.
“Careful with that, you could hit someone with this if you wave it around like that.” Wei Ying says and Lan Bin apologizes immediately, bowing to his teacher with only a few incorrect gestures – he curled his fingers inwards and didn't bend his back, which were small inconsistencies easily corrected through time and practice.
“Perhaps Lan Bin would like to take lunch with me and we can discuss how much he likes his teacher?” Lan Wangji says, walking forward to hold his hand out for Lan Bin to take. Wei Ying makes a high pitched noise, his hand going to his chest, while Lan Bin stares at the offered hand suspiciously.
“A-Die says that being married is wanting to be with a person all the time and loving them lots and lots and I love Teacher Wei lots and lots and he's my favorite person.” Lan Bin says as he takes Lan Wangji's hand in his own.
“That is true.” Lan Wangji says, looking up to smile at his husband. “Wei Ying is my favorite person and I never tire of his company.”
Wei Ying wails, covering his face, and complaining about sincere Lans who were out to kill him with their words.
“I guess you can stay married then.” Lan Bin says with a pout as they start off towards the main common areas.
“I thank you very much for your blessing.” Lan Wangji says, completely seriously.