Darcy feels herself reaching new levels of irritation every time Bucky twitches and knocks her wrench loose from its grip on the nut to the screw she's supposed to be tightening. The repair to the foot clamp of his Conn-Pod harness would be over by now, but the dumb jerk-face just keeps showboating for Mako despite his knowledge that she's Becket's girl.
Darcy glances at Steve who is quietly watching the whole scene from the other side of the Conn-Pod and he just shakes his head in a combination of exasperation and amusement.
All the while Bucky is still trying to impress poor Mako and when he actually makes her drop her wrench, she snaps; "Dammit Barnes, if you don't stay still, I'm gonna shove this wrench where it ain't shiny!"
Steve snorts and Mako snickers, but ultimately the best result of her promise is Bucky's silence.