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"Papa, how come Luc doesn't speak like us?" Kaeya had asked Crepus one night. He had wanted to ask this question for a long time, but wasn't sure if it would cause trouble. Finally, he was tired of wondering. He had purposely waited until his older brother had fallen asleep, because he didn't want to upset him. Kaeya noticed very quickly that Diluc never liked when his disorder was spoken about.
"Well," Crepus takes a deep breath, mulling over the easiest way to explain the answer. "Your brother...was not born with the ability to speak like you or I. His mind works just a little differently than ours does."
"Different how?" Kaeya props his head up on Crepus' knee, looking up at him as he waited for another answer. "Is he sick?"
"No, no. He is very healthy," Crepus smiles, ruffling Kaeya's blue tuffs. "He just...views the world in a different way than most people. What might seem simple to you, may not be simple to him. For example, speaking." Kaeya remains silent, trying his best to understand his adoptive father's words.
"Can we teach him how?"
"I'm afraid not, dear boy," Crepus exhales a sorrowful laugh. "We can teach him lots and lots of things but he is unable to talk." Kaeya frowns, glancing at his sleeping brother. It didn't seem fair. How come everyone else gets to talk but Diluc can't? He deserves to have conversations and sing like Kaeya, and all of their friends.
"Can I talk for him sometimes?" If Diluc couldn't speak, then maybe Kaeya can be a good brother and do it instead. If Diluc will let him.
"I bet he'd appreciate that of you very much." Kaeya smiles as his father pets his hair. "Your brother is very smart. Don't forget that."
"Who's that over there? He seems to be off in his own world." The visitor points towards a bright, red headed man, who was sat on a bench watching the birds drink and play in the water fountain.
"Ah, that is my brother. Diluc," Kaeya announces, glancing behind himself. The man looks up at the sound of his name, being lulled back to reality.
"Hello, Diluc. My name is Cesiel and this is Roman. We just arrived in Mondstadt a few days ago and your brother is showing us around." Diluc offers a small smile and a quick nod of his head before returning to his bird watching. "Hey! Don't you know ignoring people is rude-"
"He doesn't speak." Kaeya says sharply, cutting the man's words short. "He is very kind. Please don't assume the opposite." The man scoffs, rolling his eyes. Kaeya bites his tongue, for now.
"Nice to meet you, Diluc," Roman chimes in, offering a friendly wave. Diluc waves shyly back, another delicate smile across his face.
"Now then," Kaeya clears his throat, feeling awkward at the tension that was created. "Shall I show you all the tavern? Diluc here is the best bartender in Teyvat."
"He doesn't know how to speak and you think he can work a bar?" Cesiel snorts, shaking his head. Kaeya felt his blood begin to boil. It was a Mondstadt custom to greet all passersby and travelers with hospitality, but this man was making that more and more difficult by the minute.
"I don't see where those two things correlate," Kaeya says monotone. Diluc, who was beginning to notice the commotion, stands up from the bench and approaches the group. He looks at Kaeya and taps his wrist three times. "Alright, go on. I'll meet up with you later." Diluc nods and leaves the area. Kaeya turns back to his unfortunate guests and clasps his hands together. "Tavern?"
"Where'd your grown child head off to?"
Kaeya stares at the ground for a moment, debating his next words. Or actions. "Gentlemen," he says lowly, turning his back to them. "Follow me." Kaeya leads the men down a vacant alleyway and once he's sure they're far enough from the public eye, he presses his arm on Cesiel's chest and pins him against the side of the building.
"Listen to me very carefully," Kaeya growls, staring into the man's eyes. "My brother is one of the smartest people I know. His speech is no concern of yours. He is very capable of taking care of himself and he is half the person you wish you were. If you so much as look in his direction again I will make sure that he speaks more words than you ever will again." The man shakes beneath Kaeya's grip, too scared to responds. "Are we at an understanding, outlander?"
The man quickly nods his head and Kaeya lowers his arm. He claps his hands together, dusting them, and straightens his clothes. "Now then," he smiles, "I do believe you're both smart enough to discover this place on your own. Good day." Kaeya exits the alleyway, leaving the stunned men behind. He makes his way to his and Diluc's secret location, where Diluc signaled he'd be waiting at. When Kaeya appears, Diluc approaches him quickly, worry spread across his face.
"Don't worry," Kaeya chuckles, waving his brother off. "I didn't hurt anyone." Diluc grumbles and nudges Kaeya's arm. "I'm sorry, okay! But I'm not going to let a stranger talk about you like that. Absolutely not." Diluc huffs but lets it go, because he knows arguing with Kaeya is futile. "Are you okay? Be honest."
Diluc nods. "You're sure." He nods again. "Alright. Let's go get dinner." Kaeya throws an arm around Diluc's shoulder and roughs up his hair, earning a shove and another irritated noise. "Don't even pretend you don't love me," Kaeya smirks. Diluc huffs one last time, but Kaeya sees the smile he tries to hide.