Work Text:
There were a lot of words Gen could use to describe Senku, though depending on the day they might not all be complimentary.
Diligent, focused, brilliant, kind, utterly mad…
Tactile, though, wasn’t one that ever came to mind.
While Senku never admitted any sort of official diagnosis and Gen didn’t want to overstep, he’d put quite a few dragos on the fact that the other man was at least some sort of neurodivergent. Between his lack of (and complete disinterest in) social graces, his intense hyper-fixation on science and all that it entailed at the expense of all else, and his obvious discomfort and difficulty with expressing his feelings, Senku certainly checked quite a few boxes.
One of the most obvious things that had flagged for Gen, though, had been Senku’s aversion to touch.
As a mentalist, Gen was keenly aware of the interactions of those around him - taking each and every cue to better hone his understanding of a person and formulate the best way to approach them. He’d seen how Senku ducked away from Chrome’s attempts to pat his arm, casually avoided Ginro’s odd habit of trying to sling an arm around his shoulder, the careful distance he tended to keep between himself and others - just out of reach without being obvious about it.
Gen could see the way Senku would tense up when someone managed to slip past his defenses - Magma clapping him hard on the back, Suika racing up to fling her arms around him excitedly - momentarily off kilter before he righted himself. And almost imperceptible shudder racing through him, a blink-and-you-miss-it deer-in-headlights fight-or-flight twitch carefully reined in and powered through. To most it probably looked like surprise, but to Gen the distress was palpable.
Though, to be fair, it wasn’t that Senku was completely opposed to physical touch - Senku initiated fist bumps and high fives regularly in moments of triumph and congratulation. He had no issue with grabbing someone's arm to drag them where he wanted or give a shove when warranted. And when an approach was clearly telegraphed or he was particularly familiar with someone he barely seemed affected - though even Taiju’s overzealous bear hugs were expertly dodged more often than not.
In short, when the two of them finally acknowledged the thing between them and officially started dating Gen hadn’t expected much in terms of physical intimacy.
“Hello, darling,” Gen murmured as familiar arms looped around his waist, a warm chest pressing against his back and a bony chin resting on his shoulder.
Senku grunted, peering past him to the sprawl of papers on the table with an idle curiosity.
“Just some inventory sheets for Ryusui-chan,” Gen replied to the unspoken question, smiling when Senku made a considering sound in response before bumping the side of his head against Gen’s insistently.
Clicking his tongue, Gen reached up to comb his fingers through the hair on the back of Senku’s head. The reaction was instantaneous - not visible enough that anyone else would have noticed, but Gen could feel how Senku practically melted against him. The tension that perpetually lived in his shoulders loosened, his hold around Gen’s waist tightening as he leaned more of his weight against him.
It had been a pleasant surprise, learning just how much Senku actually liked being touched.
Not publicly, of course, he still dodged most casual contact from everyone else with the same efficiency he always had. If Kohaku grabbed his wrist to drag him somewhere, he tolerated it with long-suffering resignation until the first chance he had to pull away. When Taiju managed to catch him in a rib-crushing embrace he endured it for approximately three seconds before shoving and wriggling to escape. Suika was given the most grace, but even her surprise hugs were usually cut short by a clever distraction or new task.
With Gen, though, it seemed all bets were off.
It had started small - a shoulder pressed against his while they worked, a hand briefly catching on Gen’s sleeve as they walked through a crowd, knees touching beneath the table during meetings.
But seemingly overnight it had escalated to… this.
Senku never directly asked for contact - in fact Gen suspected the other man would implode in on himself if he even tried to verbalize the request - instead he would just… appear.
Gen would sit down and within minutes there would be a warm weight leaning against his side. He’d wake up to find Senku coiled around him like a koala, face buried into Gen’s neck and legs tangled with his regardless of the weather. Senku would drop his head against his shoulder without warning, nudging him like a persistent house cat until Gen started stroking his hair.
It was honestly rather adorable, even if Gen knew there was no way Senku would ever acknowledge just how touch starved he was.
“You know,” Gen hummed affectionately, fingernails scratching lightly against Senku’s scalp, “if you want my attention you can simply ask.”
Senku made a noise somewhere between a scoff and a grunt, face still half buried in Gen’s shoulder, arms tightening even more. “…This is asking,” he muttered.
That earned a quiet laugh and Gen turned his head just enough to press a kiss into Senku’s hair, fond and unhurried. He could feel Senku exhale sharply through his nose, not quite a snort but close, though it lacked any real bite of annoyance, smiling into the pale strands as Senku all but sagged against him.
“Have I told you recently how cute you are?”
“Gross.”
Despite the complaint, Senku made no attempt to move away, instead leaning closer. His nose brushed against the side of Gen’s neck for half a second before he stilled again.
It was a tiny gesture, but one Gen was swiftly growing familiar with - a small, unconscious seeking motion.
Absentminded nudges that he doubted Senku even registered he was doing. The way his fingers caught on Gen’s while they walked, how he drifted closer whenever they stood beside one another too long, his habit of hooking an ankle around Gen’s just as he fell asleep as if trying to hold him in place.
A stubborn little instinct rearing its head when Senku stopped thinking about it.
It made something warm expand in Gen’s chest every time.
“You’re tired,” Gen observed, smiling at the noncommittal grunt he got in response. “Did you come here for a reason or just to use me as a heating pad?”
“Why can’t it be both?”
Laughing, Gen turned properly in Senku’s hold and looped his arms around the scientist’s shoulders. The reaction was almost embarrassingly instantaneous, Senku exhaling deeply as his body folded forward into the embrace like a flower towards the sun.
Like his body recognized safety and comfort before his brain had a chance to argue.
It was almost overwhelming to be trusted with such intimacy, such quiet, instinctive need. Trusted with the parts of Senku that he never let anyone see.
“You know,” Gen murmured, thumb brushing idly just behind Senku’s ear in a slow metronome, “you’re very different when no one else is around.”
“That’s because no one else is around.”
Gen laughed softly. “Hmm, there’s my charming conversationalist.”
“Shut up.”
The words lacked all conviction, Senku’s voice low and rough with exhaustion, words slurring together in a way that signaled he’d been awake for far too long again.
Carefully, Gen threaded both hands into Senku’s hair, massaging slow circles against his scalp, humming as the other man melted further against him. If someone had told him a year ago that Senku would not only willingly seek out affection, but that he was a cuddler, he would’ve laughed in their face.
And yet…
“C’mere,” he said, guiding Senku sideways to where he had shoved their bedrolls against the wall instead of putting them away that morning. It wasn't a far distance, but it was a careful shuffle to make without letting go of the sleepy scientist.
“I was already here.”
“Ah," Gen agreed sagely, sinking them down to sit on the floor, "but now you can be here horizontally.”
Gen had barely settled his back against the wall before Senku was folding over and dropping directly into his lap as if their current position had been his plan all along. Blinking for a moment, Gen couldn’t help but laugh as Senku got comfortable, cheek pressed into his stomach as an arm hooked loosely around his waist.
“Are the accommodations to your liking?” Gen said lightly as he threaded his fingers back into Senku’s hair, biting his lip as his chest swelled at the way he sighed and leaned into the touch. “You know I adore you, right?”
Senku peeked an eye open for a moment before pointedly burying his face further into Gen’s stomach with a huff of obvious embarrassment.
“Ugh,” he complained into the fabric of Gen’s yukata, the shell of his ear flushing scarlet against the pale platinum of his hair, “you’re being weird again.”
Gen laughed, leaning down to kiss the top of his head, but didn't respond. Senku grunted and Gen could picture the shy little pout he was trying to hide, rolling his eyes when Senku pressed his forehead against him more firmly and beginning to card his fingers through his hair again.
It only took a few minutes for the remaining tension in Senku to ease, his breath slowing, body going fully limp against him and Gen shook his head fondly when he realized he was truly and fully dead to the world.
"Well," he murmured, delicately tracing a finger over the lines of Senku's profile, "suppose this means I'll be trapped here forever."
His fingertip brushed over the lobe of Senku's ear and the scientist made a sleepy sound, curling his face deeper into Gen's stomach and blindly tightening his hold around his waist without waking. As if to ensure exactly that.