No one treats Hirato like this. No one's ever treated Hirato like this.
On nights under Akari's directive, when the doctor's the one doing the taking, the captain invariably notices how warm palms slip over his battle-weary flesh—slow like honey, meticulous in their traversal and so finely controlled that occasionally he feels a bit like an experiment himself. He's well aware that the blond's hands are likely cold under routine circumstances. They must be inordinately tired, too. A researcher's long hours pass in temperature-controlled labs and overly air-conditioned hospital suites, after all. But Akari never handles Hirato's bare skin with icy or fatigued hands.
The commander thinks this cautiousness is unnecessary, naturally. He's a soldier, a fighter, and he certainly does not require a light touch. His body's seen enough damage to be inured to significant physical pain. Even so, on these evenings Akari kisses him like he's fragile, breakable—a trinket forged from delicate glass or an insubstantial phantasm conjured by magecraft. Velvety lips cling to his for the briefest of instances before they trace the same patterns that the doctor's fingers have lately etched. At first, Hirato was unconvinced that such subtle technique could satisfy him, much less exhilarate him. Being wrong was never so gratifying. Unhurried as they are, Akari's ministrations send him careening off the cliff of sanity without fail.
One night, while enjoying the sated quiet that inevitably follows this exquisite pleasure, Hirato's curiosity prevails over his nonchalance. Akari is fitted against him, the physician's impossibly long legs tangled with his own. Those exacting, deliberate fingers lightly sketch spirals along his collarbone. Soft, steady breathing tingles sensitive skin as a curved mouth settles against his neck.
Hirato takes the blond's hand, drawing him away from lazy contemplation. Searching crystalline eyes meet his. "Sometimes you're so careful with me, doctor." A tiny crease forms between light-colored brows, and the memory of a rather spirited conversation regarding formal address and its appropriate contexts comes to mind. He smirks. Teasing his lover is always apropos. "Are you fearful of breaking me?"
"As if anyone could," Akari huffs incredulously. But his cadence betrays affection.
"Just accustomed to surgery, then?" Hirato counters playfully.
The researcher only leans in and captures his lips. There's meaning lingering beyond this gesture, but it escapes him. "Tell me," Akari's tone is subdued, "Can you recall a time when your body, when your life, wasn't subject to Circus' utilitarianism?"
He stills.
"You may not be easily breakable or fragile, Hirato, but it's erroneous to presume that invulnerability diminishes your worth. Do not confuse me with them again."
No. No one else could treat him like this, because he really is breakable, and only Akari possesses that knowledge.
NB: Real relationships don't conform to seme/uke tropes. Just, FYI.