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Rin is in his lap again–just where Sae wants him; where he belongs. He fits so perfectly that Sae doesn't even have to adjust him anymore. His little brother just knows how to settle in, soft and quiet, like something well-trained.
His body is soft and feather-light. His legs dangle uselessly over the side of Sae's thighs, kicking once in a while like he's forgotten they're not supposed to be swinging. They don't even reach halfway down Sae's thighs–still too short, still too small.
Sae watches the motion with a blank expression, his eyes half-lidded. There's a book open, balanced across Rin's knees–a picture book filled with bright colors and cartoonish animals, the kind Rin insists on reading aloud even when he stumbles over the longer words. He's narrating something with breathy excitement, but Sae isn't really listening, really.
Instead, his arms slide around Rin's waist, low and loose at first, then slowly tighter until Rin is caged in, wrapped fully in the circle of his older brother's limbs. His fingers meet effortlessly at the front, settled just beneath his little brother's ribs.
He tightens the grip, just slightly. His thumbs overlap across Rin's belly, and his pinkies graze the jut of the child's hip bones. It should worry him-how easily Rin fits, and how lightly he can hold him down. But instead, it fills him with an odd warmth.
A quiet breath escapes him as he rests his chin on Rin's shoulder, nose brushing lightly along his neck. He inhales deeply, drawing in the lingering scent of the sweet shampoo he lathers into Rin’s hair every bath night. Beneath it, there's something else; something warmer-childish, clean, and too much like Rin.
His thumbs begin to move slowly, stroking lazy circles into the soft stretch of skin beneath the thin fabric of Rin's shirt. One thumb dips into the hollow of his belly, presses gently as if testing the ripeness of a fruit. The other hand slides up his side, fingers lightly tracing the curve of his ribs. He can feel bone beneath the cotton shirt and soft flesh, the flutter of breath, the steady thump of a tiny heart.
And Rin? Ah, he doesn't even notice–of course, he doesn't. He just shifts a little, leaning further into Sae's chest, humming as he flips another page, too engrossed in reading the story to his Nii-chan. And when he glances back over his shoulder to check if Sae's still there and listening, Sae offers him a soft, quiet smile. Gentle. Warm. Carefully curated.
He closes his eyes, breathes, and controls himself. He loves Rin, after all. He doesn't want to hurt him. But love is a complicated thing when it rots. So he does what he can., he kisses the back of Rin's neck instead. Soft. A brush of lips. Nothing more.
Rin squeals and giggles, a shrill, startled sound. "Nii-chaaaaaan..." he whines, squirming without real resistance. "that tickles!" The book wobbles on his knees, nearly tipping off. His little hands scramble to keep it balanced.
Sae doesn't move. His mouth lingers near the same spot, lips still ghosting over the back of his neck, "Sorry." he murmurs, but the smile that curves his lips is slow, private, and far from apologetic. He shifts his grip and pulls Rin closer, flush against his chest. His fingers stay splayed over Rin’s front, now warmed by contact.
He wonders if Rin can feel his heartbeat. How heavy it is–how wrong it sounds. But Rin just sighs, and leans further in, book now forgotten in favor of curling against his Nii-chan's chest like a kitten curling into warmth. Sae closes his eyes again. And this time, he lets himself hold the boy just a little closer than he should.