One day, deep into their lives, reality slaps him in the face quite suddenly.

It's a mundane moment full of mundane things. Childe laughs warmly, that well-known, rapscallion smile spread wide across his face. He nudges Zhongli's shoulder with his own, warmth seeping in through the thin cotton of Zhongli's shirt.

Zhongli loves him, what was once a small kernel of feeling now bursting full in his heart.

But then, Childe turns to face him and Zhongli sees the lines around his eyes, and the creases around his mouth. Silver sprinkles throughout his hair, capturing the Liyue sunlight. Childe isn't old by much standard, he's just older. Still mostly in his prime and beyond capable.

He is weathered, well-seasoned, more of a silver fox nowadays than a vibrant red one, and though handsome and distinguished, Zhongli can't help but frown.

Zhongli loves him, and that's why his heart tugs sideways as an inevitable weight finally falls upon him, anchored like the stone that he carved his beloved home from: Childe is mortal and he does not have forever.

It takes Childe a moment to notice. He nudges Zhongli once more and says, "Hey, what is it?" His eyes glint brightly now, so unlike the dull ocean blue of his younger years.

"I was only thinking."

Childe waits, patiently. In his youth, he wasn't so composed, but the years have mellowed and tempered him. When Zhongli doesn't answer, he smooths his thumb over the bone of Zhongli's wrist. "All right then, whenever you're ready."

Zhongli is not an easy man to read, but Childe is fluent in their love language. And so, he says, "Later."

When later comes, though, Zhongli is distracted.

Their room is dark and the air cold, the biting winter slipping in through the cracked window. Childe is below him, his front pressed to the bed, his face suffocated by the sheets. His fingers curl into the soft silk, yanking at it.

He cries out, a wanton sound that Zhongli tucks deep into his gut so he'll never forget. He grips Childe by the hips and fucks into him, hard, maddening drives that strike the perfect spot. Childe keens, rutting back against him, raising his hips to meet every thrust.

Zhongli watches as his cock slips into him, how Childe's ass pulls tight around the thick length, his rim puffy and slick.

"Perfect," murmurs Zhongli, wiping at the sweat that beads on his brow, "So, so perfect for me." Even now, with Childe's aching joints and the way that he can't always straddle him. With the scars that mar his imperfect skin, and tiny little stretch marks that show the softness he's gained with age.

Zhongli palms at his ass, spreading the cheeks wide. Grunts lowly as he fucks in hard and fast.

"Gods— oh, oh, gods," cries Childe, his voice cracked and pitched high. He whines underneath him, wriggling his hips, trying to get any friction he can against his hard and leaking cock that bobs beneath him.

"Darling," murmurs Zhongli, thinking of his husband, thinking of their love. Thinking of how tight his ass is around him, and how well he takes his cock.

He also can't help but think of Childe's mortality, and how he won't have this forever. About how there will be a day where his hands will have nothing to grip tightly, and no tight heat to fuck into.

No one to worship with the warmth and depths of his heart; no one to wholly, and utterly complete him.

Zhongli isn't the type to dwell on things, so the slight stutter of his thrusting is odd. He feels like a stranger in his body, his brain consumed by these unwanted thoughts. Childe doesn't notice, too lost in his pleasure, too drunk on the drag of Zhongli's cock as it presses against his prostate.

"Fuck," hisses Childe, when Zhongli plasters himself against his back, wrapping an arm around his waist to grab at his cock. Hard in his hand, leaking so perfectly— Childe comes nearly the moment Zhongli squeezes it tight, his ass tightening so much around him that it punches the breath from Zhongli's throat.

Zhongli presses his nose into the nape of Childe's neck, his eyes slipping closed as he just breathes him in and feels him. The way that Childe's ass flutters around his cock, milking him dry; how Childe moans below him, debauched and breathy; how he squirms with overstimulation.

The smell of the ocean and salty sea air, and that sandalwood soap that he loves to bathe with.

"Please," cries Childe, "Archons, Zhongli— Please—"

Zhongli fucks in deep, grinding against him, Childe's ass flush against his hips, dick nestled in as far as it can go. And Zhongli just holds there, gripping Childe tight, the baby hairs at the top of his spine tickling Zhongli's nose as he tries to ground himself and all these wayward feelings.

"I love you," he says, his lips and tongue tracing the salty skin there. "Gods, I love you Ajax." Zhongli nips at him and Childe keens. And then he fucks back against him, overstimulation be damned.

Zhongli smooths a hand down his side, touching every inch of Childe's skin that he can manage. He tries to commit it to memory— the sight, the taste, the smell, and the feel of him. How Childe wriggles, arching his hips. How his cock stirs again at the barest touch.

Zhongli is unwavering stone, his memories perfect in their recollection. And while the mere memory of his husband might not be enough, in the end, he'll still have it. It'll accompany him into the pits of whatever erosion eventually weathers him away.

He never cries, but he feels the tears that leak at the corner of his eyes. He doesn't sob, but he hides an embarrassed sound against the back of Childe's neck. Zhongli wondered what it was that made mortals tick, it's why he retired and walked in their shoes.

And now he knows, that dreaded feeling of humanity tugging at his core. He loves so deeply that it'll turn into loss next. Zhongli feels death as it looms over him, watching from the end. Even if it isn't his own.

This is what drives them, he realizes, that bare understanding of finite existence. Mortals do what they can to make the most of it.

"Zhongli," says Childe tiredly, even though his cock twitches.

"Ajax." Zhongli shifts, changing angle as he leans Childe's shoulder and presses his mouth near Childe's ear. "Darling," he whispers, "One more—"

"Oh, fuck."

"Just one more, come on my cock. I just want to remember this."

It won't take much. Zhongli can tell as he fucks into him again. Childe goes taut underneath him, fingers white-knuckled in the sheets, his thighs tense and shaking. His ass sucks him in, wringing Zhongli dry.

And he feels it too, the way that his orgasm churns in his gut. The pleasure that mounts higher and higher, rising through his being and coiling tight in his belly.

"So good for me," he says into Childe's ear, uttering filthy, filthy, debauched words as he does his best to carve him open and stake his claim forever. "So tight—" Zhongli squeezes at his hip— "So warm."

"I'm— I'm—"

Zhongli fucks into his prostate, over and over, cruel in the way that he pounds against it. It's a carnal thing, though loving. His cock slips in deep on every downstroke, Childe's rim parting as though to let him right in.

"Oh, my husband, my mate, my everything." Zhongli's breath hitches against his neck. He feels the dragon lurking, deep in his mind, urging him to claim—

Zhongli bites him, teeth sinking into the meat of his shoulder, right where it meets his neck. And Childe yelps, tightening around him, fucking back against him with wild abandon. Then he comes again, this time untouched and only on Zhongli's cock, spilling all over the sheets with thin and dribbling spend.

"I love you," murmurs Zhongli, a reverent whisper into the night. And he keeps murmuring it, over and over with every thrust of his cock until, he too, tips right over the edge. He fills Childe up with a hoarse moan. Zhongli breathes hard against him as he collapses against Childe's back.

He hides the tears, pressing his face into Childe's sweaty hair, even as his shoulders wrack with quiet sobs.

But Childe knows, he knows, because he's already moving, wincing slightly as Zhongli's cock slips out. He turns underneath him and reaches up, pulling Zhongli to his chest.

And Zhongli collapses against him, uncaring of his weight, or the mess, or how tired and sweaty they are. He sinks into his husband's touch as Childe strokes his fingers through his hair.

"Shh," soothes Childe, pressing kisses against his temple. "Im here," he says, "I'm not going anywhere."

But he will. Eventually. And then Zhongli will be so hopelessly alone.

It will not be the first time. But it will be the last.

Later, when the punch-drunk and floated feeling of his high fades, Childe finally broaches the topic. "I'll find a way," he says simply, oozing that confidence of his youth, as if this is just another Ruin Gaurd on his patrol.

"Ajax." Zhongli sighs, soft and exhausted. Too exhausted to be having this conversation.

"A promise. No— a contract, you love those."

Zhongli hasn't made a contract since he married Childe— officially— swearing soft words of love in the depths of their Serenitea Pot. And even then, he'd broken his own promise of a contract to end all contracts.

"A solemn oath, etched in stone," says Childe against him, his mouth warm against the skin of Zhongli's brow, "I'll find a way where I won't have to leave you."

It's romantic, he thinks, how Childe wants to fight for their love. How he's just as willing to chase right after it because he refuses to leave Zhongli empty and frail. Two sides of the same Mora, truly.

"Please." It's a quiet beg. And begging isn't something that Childe does unless he's on his knees and begging to be fucked. "Let me have this one thing, one last noble quest."

Zhongli falls quiet as he thinks. He says nothing because he knows that Childe's mind is set. He will try to talk him out of it later.

Instead, he shifts slightly, pulling Childe's hand to his mouth. He kisses the ring on his finger, the solid band of geo, crafted by his very own fingers. My love for you, etched in stone, inscribed inside, nestled right against the vein that goes straight to Childe's heart.

"Etched in stone," he murmurs, his voice rumbling low against Childe's chest.

"Always," says Childe.