He got injured on a mission... again.
She helped him... again.
"Barton?!" Natasha's voice was crackling, and all Clint could think about was how bad the signal over their comms was. A slight grin ghosted over his face as he glanced down at his leg, then swore under his breath. "I've been hit," he muttered raggedly into the comm, letting yet another arrow fly before hobbling into an alcove. She was more than capable of dealing with the last person. His bow lay ready on his lap, an arrow notched, as the redhead came into view, firing one last shot. Her eyes flickered to him and she rolled them, almost groaning. "Typical," came her wry voice, and she hurried over, dropping to her knees in front of him.
Natasha's fingers moved deftly over the bleeding wound in his leg. "You've got to stop getting hurt on these missions. You're not immortal." It wasn't just Clint who flinched at the coldness in her voice. It sounded callous to her own ears. Surely a girlfriend should be more concerned. Then again, this was Natasha's way of dealing with worry. Brusqueness masked fear; harsh words hid her true feelings. A quick breath in, a tug at the edges of the wound that was just slightly rougher than was strictly necessary, and Natasha's emotions were back in check. "I don't want a dead boyfriend, Clint," she murmured quietly, her emerald eyes flickering up to catch his strikingly blue ones, although they were more stormy grey with pain. There was a long pause as she focused on his injuries, broken only by his ragged breathing, before his voice spoke up roughly. "How about a husband instead?"
Had Natasha misheard him? Her eyes searched his for any hint of a joke. He couldn't be serious. "You've lost a lot of blood, Clint. You're not thinking straight." Clint rolled his eyes, stopping her hands for a moment. "Just stop for one second, Natasha, and answer me. Will you marry me?" It wasn't the most romantic proposal, but to her, despite the blood, the bodies piled around them, the exhaustion, it was perfect.
Neither of them meant it to happen.
They saved each other...
Again.