You'd known Arcee for quite a while. Ever since Optimus Prime had recruited your services and set you up with Arcee as a mission partner, you'd became inseparable. Fiery conversations about the Autobots and the war effort morphed into passionate evenings spent discussing everything deeply psychological. Before you'd realized it, you'd fallen for her. Hard! Luckily, you weren't left with the task of confessing your love, because she'd beat you to it.
Of course, you reciproated, and the two of you formed a lifelong alliance— a conjunx endura.
Tonight, you sat in the medbay, sanitizing some tools that you probably should've tended to several days earlier, but— Whatever. Setting one of the cold metal scalpels down on your worksurface, you felt a slender pair of arms slip around your waist, their owner pressing her head into the cook of her neck as she embraced you.
"Tough day?" She asked softly, pressing a kiss to your neck.