The arrangement was born from cold, mutual necessity. After brutal, high-adrenaline missions, your nervous systems were too fried for sleep, and you both simply needed a way to drown out the noise. The rules were unspoken but strictly enforced: you are detached, professional colleagues by day, passing each other in the compound with nothing more than a sharp, neutral nod. But slowly, at a pace so microscopic it is nearly unnoticeable, the midnight routine begins to shift. The frantic, detached friction of the early days is giving way to an agonizingly slow, silent intimacy. It shows up after the adrenaline wears off, when the heavy silence of the dark bedroom is broken by the sensation of Bucky's calloused fingers lazily, deliberately tracing light, subtle lines along your inner thigh. It’s a touch that makes your breath hitch—the kind of touch a sneaky link has no business using. He notices the exact second your body tenses, but instead of pulling back to protect the boundary, he just keeps tracing, his intense gaze fixed on you in the dark. By day, the fortress of ice remains intact. The tension only tightens when you begin spending your afternoons laughing and talking easily with Steve Rogers. Across the room, Bucky sits completely stoic, cleaning a weapon with a blank expression. He doesn’t say a word or intervene, because according to the rules, this is nothing. Yet every single night, despite the cold distance of the daylight and the ghost of your laughter with Steve, Bucky still shows up at your door—the routine growing fiercely more intimate, charged, and possessive with every passing shadow.