Diluc’s first mistake was failing to answer Kaeya’s question about how often he needed to feed.
They make it back to Mondstadt faster than Kaeya would have liked - he wanted more excuses to talk to Diluc in private - but he sees Diluc off on the path to the Dawn Winery and promptly heads back to Mondstadt, himself, not exactly feeling welcome at the winery. It’s rather unfortunate to be separated from Diluc so quickly, only because Kaeya could have milked more information from him, but it is what it is.
... Naturally, Kaeya’s sneaking into the winery the next night.
Diluc’s broadsword is pressed to his throat again, and Kaeya grins, keeping quiet as he speaks, “C’mon, can’t you greet me with less hostility?”
Diluc rolls his eyes, but sheathes his blade again. “You’re the one who broke into my room in the middle of the night, what did you expect?”
“Pretty much that, actually.”
“Then don’t complain. What do you want?”
“Well, you never answered my question, before. I get that you don’t like talking about it, but how am I supposed to make sure you stay fed if I don’t know how often I’m supposed to feed you?”
Diluc frowns. “... Your phrasing makes me sound like a pet. I’m perfectly capable of coming to you on my own when I need to drink.”
Kaeya hums. “Sure, but would you?”
Diluc closes his eyes. Kaeya slings an arm over his shoulders, ignoring the way Diluc immediately attempts to shrug him off. “C’mon, c’mon~ it’s fine, right? I’m volunteering and everything. And didn’t we agree that it makes more sense for you to take less but more frequently, since you’re worried about making me weak again?”
“Less and less concerned about it by the second.”
Kaeya snickers. “Then bite, and take as much as you want.”
“I could kill you.”
“So? So could most things. Doesn’t make you special.”
Diluc turns, not trying to get out from Kaeya’s arm anymore, instead simply pressing fangs to Kaeya’s neck, but not biting yet. Kaeya doesn’t tense, doesn’t do anything other than tilt his head away to let Diluc have as much room as possible to bite if he’s going to.
He doesn’t. “... Your pulse...”
... Ah, Kaeya supposes he should have figured Diluc would be able to hear it. “Mm? What about it?”
“It’s a little fast.”
“I’m not afraid of you, if that’s what you’re worried about.”
Diluc lifts his head; it puts their faces rather close together, and Kaeya backs up just a little, but definitely not out of fear. Still, Diluc watches him, and seems to have taken his flinch as such, because he huffs, “It’s sensible to be worried about it anyway...”
Kaeya laughs. “Really, I’m not lying. It’s not fear.” Diluc should have heard it pick up even further just now, but that’s not the kind of conversation they’re going to have right now. “Anyway, are you going to drink tonight or not?”
Diluc tilts his head again, murmuring against Kaeya’s neck, “Just a little, then.”
Kaeya tilts his head back once more, and Diluc bites him gently again. That kind of tenderness... Kaeya wouldn’t mind it a bit rougher.
Being gentle and sweet like this... too much has changed. They’re not who they were back then, no matter how much Kaeya might miss it, that connection. He knows Diluc doesn’t mean it, either; he’s only being gentle because despite everything, he doesn’t actually want to hurt Kaeya - at least not seriously - and especially with his own self-loathing for having been turned into a vampire. It has nothing to do with Kaeya himself; Diluc would be like this with anyone who wasn’t a criminal, presuming he wasn’t ravenous and unable to control himself, anyway.
Kaeya leans his cheek just gently against Diluc’s head, careful not to make him think Kaeya’s pushing him away or anything. Even so, Diluc still stops; for a moment, Kaeya worries it was too much, even such a slight gesture, but instead Diluc is lifting his head to look at his face again, seemingly worried.
There’s a bit of blood around his mouth; Kaeya can’t help it, and lifts a hand to gently brush his thumb through it. Diluc makes a slight face and pulls back, clearly self-conscious about it, so Kaeya shamelessly hugs him around the waist, intentionally too much, pushing it too far, making it seem like a gesture to annoy Diluc rather than anything sincere. “Aw, c’mon, no need to be shy, I don’t mind~”
“Like I haven’t seen a lot worse. Well, whatever, if that’s what makes you more comfortable, I guess I can’t stop you.”
Diluc looks mildly annoyed. “... It seems you’re perfectly fine.”
Ah, so Diluc had taken Kaeya’s head leaning against his as a sign of weakness. “Yup, good as gold~ Are you still thirsty? I don’t feel lightheaded or anything.”
“You leaned on me a little.”
“Well, yeah. Didn’t see the need to keep straining my neck that far. Did it make the angle bad for you or anything, though? I can go back to it...”
Diluc shakes his head. “... No, it’s fine. I just thought perhaps I’d taken too much again.”
“Nah, you’re fine. I’d say something if it got bad.”
That makes Diluc scoff, disbelieving. “No you wouldn’t.”
Kaeya grins. “... Yeah, probably not.” Still, he reluctantly lets go of Diluc’s waist, stepping back towards the window. “Anyway, I’ll come back—“
Before he can go anywhere, though, Diluc is catching his wrist. “Stay.”
... Fuck if that simple word doesn’t make his stomach twist in contradicting emotions. “Really, you didn’t take that much. I’m not gonna pass out anywhere or anything.”
“I don’t trust that you’ll take proper care of yourself. Stay.”
Well, he’s not wrong about that, but of course Kaeya can’t say so. Instead he pushes another angle, glancing around hesitantly. “... No offence, but I’m not exactly comfortable here.”
The winery... it’s not Crepus’ mansion - Diluc sold that - but it’s still a place they spent a lot of their time together when they were younger. It’s true that he’s not quite comfortable here, but it’s not... entirely because of the staff and the negative memories.
The pleasant ones are just as lethal. Diluc’s own bed... Kaeya really doesn’t think he can sleep in it as if everything is fine. The number of times they’d done things other than sleep in that bed...
He has no idea about the status of the room he used to occupy, but whatever it is, he’s definitely not comfortable sleeping there, let alone leaving Diluc’s room to even get there, lest he be seen by one of the staff. It’s not like he thinks most of them would be hostile or overtly rude to him - though some of them would - it’s just because it’s awkward to face them, especially since he came in through Diluc’s balcony and all. The last thing he needs is them thinking he came here to pick a fight or something.
So, if he can’t leave Diluc’s room to go elsewhere in the winery, and he can’t stay in Diluc’s bed for his own sanity, the best thing to do is leave.
Diluc watches him again. Kaeya meets his gaze, but tries to convey an expression of slight tension without being blatant about it, just something subtle, to make it believable.
Kaeya’s not sure what it is, but Diluc, unfortunately, seems to have something of an epiphany as he glances back at his own bed. His cheeks flush just slightly, and even when he turns back to Kaeya, he doesn’t quite meet his eyes. “... Right. Then, at least drink some water before you go.”
Kaeya’s relieved, even though Diluc’s reaction to what must have been the memory of what they last got up to in that bed together is a bit confusing. He doesn’t seem disgusted or upset, which Kaeya had expected; oh, he’s not stupid enough to get his hopes up, to think that maybe Diluc misses him the same way, but it’s interesting nevertheless. Kaeya smiles easily to clear the air. “If you insist. Assuming you’ll go get it for me?”
Diluc nods, seeming to understand now why Kaeya’s not exactly thrilled at the concept of roaming the winery. “Okay. Sit down in the meantime.” Then, boldly, “For my sake, if not your own.”
Kaeya raises an eyebrow, impressed that Diluc would say it. “I’m doing things for your sake again now, huh?” But he’s not trying to be difficult, so he sits in a nearby chair nevertheless. “Alright, alright.”
“If only you were always so obedient.”
For you, I could be. Alas, Kaeya’s definitely not going to say that right now; normally he’d have no problem at all doing so, could easily flirt and tease with no shame or hesitation, but... It hits a bit too close to home right now, and he doesn’t need to tip Diluc off.
Then again, maybe not teasing is actually more suspicious, since he usually would...?
Fuck it. Whatever. “Well, we’ll see~” There, somewhere between the two extremes, maybe.
Diluc just gives him an exasperated look and leaves to go get him the water.
... Kaeya is definitely screwed.