Why Do So Many Fanfics Have Wangxian Act So Shameless Around Each Other In Public And Around The Kids?

Why do so many fanfics have wangxian act so shameless around each other in public and around the kids? Fanfics tend to portray them acting so shamelessly until everyone around them either knows what they're doing in the bedroom or are really tired of them acting like this in public. Is this how they really act in the novel?

I think this may be due to fandom running with this particular scene:

After entering the tavern, they took a seat in an inconspicuous corner, and the waiter came over to greet them. He saw the sword at Lan Wangji’s waist, then the flute at Wei Wuxian’s. Because of their appearance and bearing, he couldn’t help but connect them to the pair who had been the subject of all the most heated talk recently. But after staring at them intently for a while, he noticed that the customer dressed in white was not wearing the Lan Clan’s forehead ribbon. Ultimately, he was left unsure of their identities.

Wei Wuxian asked for liquor while Lan Wangji ordered a few dishes. With one hand propping up his cheek and the other toying with a snow-white forehead ribbon under the table, Wei Wuxian listened to his deep voice as he read off the dishes. A wide grin was plastered on his face.

Once the waiter was gone, he commented, “So many spicy dishes. Can you eat them?”

Lan Wangji picked up the teacup on the table and took a sip. “Sit properly,” he said evenly.

“There’s no tea in there,” Wei Wuxian pointed out.

Lan Wangji filled the cup, then raised it to his lips again. After a while, he repeated,

“…Sit properly.”

"Am I not? It’s not like I’m propping my feet up on the table like I used to,” Wei Wuxian said.

Lan Wangji could no longer bear it. “Even so, do not put them elsewhere.”

Wei Wuxian was confused. “Where did I put them?”

“…”

"Lan-er-gongzi has so many demands. Why don’t you teach me how to sit properly?”

Lan Wangji put down the teacup and cast him a look. He was about to rise in a whirl of sleeves in order to teach him a very proper lesson indeed—but just then, a table at the center of the main hall burst into a chorus of roaring laughter.

Wei Wuxian likes being innocuously dirty towards Lan Wangji. But it's not anywhere near "everyone knows". We also have to remember when it came to xiao-Mianmian she even tells her parents Wei Wuxian was the "bad man" because he was being more openly dirty than Lan Wangji was, despite their little role play being on both ends . Wei Wuxian really likes being seen as the debauched next to Lan Wangji's prim and pretty self in public.

It's why Wei Wuxian jokes about no one being any the wiser that Lan Wangji can be just as much of a pervert and it not seeming to be fair. They fuck with Lan Qiren by purposefully being loud with their bed activity to annoy him and he can't do anything what with them being in their own home and married. And there is Wei Wuxian sitting in Lan Wangji's lap in front of Lan Sizhui (who they are close to so really no need for much proprietary). But the thing here when it comes to them acting as such, is because they are around designated family with those instances.

If they mess around outside of the discerning eye it's not any more radical than any other couple that plays around. There's just a skewed imagining of how couples can and cannot act with it veering into heavy purity politics despite these two acting like any other couple that's not exactly hiding they're a couple. We have the Inn lady in Yunmeng encouraging a one room after they both hesitated about one room or two room question and them HIDING they broke the tub because they had sex.

Fandom likes to think the characters in novel are a lot more discerning of Wangxian's relationship than they actually are. No one in the novel can just tell they have a thing for each other strangers or not. Only ones that encourage them or third wheel are the juniors and Wen Ning. They go on a date night in Yunmeng and it's not something necessarily out of the ordinary or remarked on in the extras (or hell even after the siege and it's Jiang Cheng getting his homophobia bit on and acting like they're being purposely disrespectful despite doing nothing out of the ordinary).

So no, it's an overwrought trope this fandom loves.