Hello! I haven't written for almost three years now, and never for this fandom, so hope it's okay. I deliberately left the ending rather ambiguous, so take it how you want to.
The first time it happens it's all his fault. They were both on a mission in Peru, simple really, but rather hard when one member of the team is continually distracted by a woman dressed in black, save for the glimpses of red and green he gets every time she turns and flashes that gorgeous smile at him. He watched her go, after agreeing that they'd meet right back here once their respective assignments were complete. They'd both decided this together, but he was the one that had forgot.
He reminded himself of that fact constantly whilst holding the trembling woman in his arms, fiery red hair now more like auburn in the dark, and her eyes, finally staring to regain their startling green hue as the broken sheen of hurt and pain began to dissolve.
He dreads to think how long Natasha sat there, waiting for him to come back. He swears to God he never intended for this to happen, but they both knew that their missions would take an hour, two at most, to complete. He should have met her by 11pm at the latest. Which is why, when he finally returns at a little past 4am, he can't help but feel nothing except regret because who was he kidding, Natasha always turned up on time. He can't believe that he would ever use her time keeping skills as an excuse, but after his mission was completed sooner than expected, he found the appeal of the nearby market food too hard to resist and decided a little stop off would cause no harm. It would be alright if he was late, after all there's no guarantee she would finish in time right? Except of course she did, and of course he forgot that they were ever supposed to meet. As he runs through the streets at 4am, eventually remembering about their plans, he contemplates whether he even deserves to go back to her. Of course he's been late back before, but it was never something he chose to do. This time he did choose, and he knows without a shadow of a doubt that it was the most selfish thing he's ever done.
When he reaches her she's mad, screaming obscenities in every language she knows. He drags her into their hotel room, not wanting to blow their cover or cause a scene. Once inside, her words became a little more direct.
"How dare you ever compromise us like that again Clint?! You absolute идиот!"
Though he never appreciates being called an idiot, he's more than used to it by now.
"I was so worried I almost got Coulson on phone! Undercover on a mission and I'm about to start begging to our handler to allow me to go searching for your stupid ass before you get yourself killed! You were 5 hours late, Clint."
He winces at the menace in her voice as she hisses his name, and he begins to turn away. He knows what's coming next, and knows there's no way in hell he will ever be able to justify what he did.
"Why did you leave me Clint?"
Well, that was new.
"I thought you weren't coming back."
He doesn't miss the catch in her voice as she struggles to get the words out, or the way in which she sounds like she could break at any moment. The sudden change in her emotions startles him, and it actually makes him stop in his tracks. He turns to face her, and he's glad he did.
He rushes forward just before she hits the ground, watching as her knees buckled and she collapsed in on herself.
"Tasha?" He questions. He's worried now.
The only response he receives is a tightening of her hands on his jacket, and then the sobs begin.
He's heard her cry before, listened outside her door as the nightmares became too much. She'd never let him in, but she knew he was there, and that was enough for him.
But to see her cry? He never had, and in a way he was almost grateful. This was completely different. He gripped her tighter as her body trembled underneath his hands, each new wave of tears bringing a shudder that even he found hard to control. He watched as her breath hitched and her cheeks turned from pale to pink, her nose starting to become red raw. Clint felt utterly helpless as the tears just kept coming, kept coming down and would not stop. He wondered if the people that made movies had ever actually seen a woman cry, because it certainly wasn't as elegant as portrayed. There was nothing pretty about seeing Natasha cry, but it was raw and honest, and to Clint that was the most beautiful he had ever witnessed.
It was only when he realised she was still sobbing, still struggling to breathe and still shaking that he realised he needed to do something.
Turning her in her arms so he held her against his chest, he began to murmur in her ear.
"Tasha Тсс ... Это нормально солнышко. Я здесь, я здесь. Мне очень жаль." Tasha shhhh... It's okay sweetheart. I'm here, I'm here. I'm so sorry.
He continued until he felt her relax slightly against him, her breathing slowing down. He didn't dare move, worried anything would set her off again.
It was only after 10 minutes of him sitting on the floor with her cradled in his arms that he began to question why this had happened. He'd returned back late many times before, and she was always mad, always angry, but never upset. He'd never seen her upset about anything really.
When a small mumble from his jacket was brought to his attention, he realised he'd asked the question out loud.
"I didn't know if you were coming back." She whispered, before taking a breath as if deciding whether or not to elaborate. "Do you remember what Fury said when I first came to SHIELD?"
He knew the answer, but couldn't bring himself to say it.
"He told me I could stay, but if it ever came between between me or the mission, the mission would come first and no one would hesitate to leave me behind." Her voice returned to its steely quality.
"He says that to all the agents Nat." Clint protested, but his voice was weak.
"No. Not like that. That was personal, directed at me. He didn't care whether I lived or died, because I was the Black Widow and he'd wanted me dead for years."
"You knows he's changed since then."
"I know, but tonight I couldn't stop thinking about it, and when you hadn't returned..."
Realisation dawned on Clint as he finished her sentence.
"You thought I'd left you behind."
She nodded into his chest, and he held her tighter.
Clint sighed, before making a promise he hoped he would never have to break.
"Tasha listen to me. I don't care what Fury or anyone else ever said or meant. I will always come to back to you, okay? No matter what it takes. Remember that. I'm never going to leave you."
The second time it happens, she knows he's coming back to her. Or at least that's what she tells herself after it's been three days since she's last heard his voice.
For the second night in a row she heads up to the roof of the tower, passing by Steve who assures her that Clint will be home soon, he always is.
She smiles back at him, but can't quite believe it herself.
So she is more than shocked when after 50 minutes of looking at stars a warm arm slides around her body and mutters "Hello."
She immediately leans back into him, feeling herself sigh with relief. Clint takes the opportunity to pull one of her hands into his lap, and begins to play with the single ring adorning her fourth finger.
She grips his hand tight, and that tells him all he needs to know.
"You didn't think I was coming back."
It wasn't a question this time. She loosens her grip, her actions betraying her. She wants him to believe she trusts him, because the truth is she finds it so hard. And though it hurts him to know she still doubts him, it hurts her more to know she might never get past this.
He knows she'll never admit it to his face, so he tries a different approach.
"Remember the night I gave you this ring?" He whispers in her ear.
He slowly begins to see her smile.
He spots her across the ballroom in an instant, but then again she is rather hard to miss. Dressed in a floor length emerald gown, her eyes twinkling as bright as the chandeliers hanging above them. He knows that this is all part of the cover, but his hands still tremble as he makes his way over to where Natasha is sat, preparing to ask her to dance with him.
"Would you like to dance with me, darling?" He adds the 'darling' as an afterthought, in an attempt to hide how utterly childish he just sounded.
If she's as nervous as he is she doesn't show it, but then again she always had been the better actor.
She doesn't reply, but instead takes his outstretched hand and leads him to the centre. Of course Mr and Mrs Clayton would have danced before, so they needed to make this look effortless. For Nat and Clint however, it was their first time.
She loves him very much, but they'd never done something like this before. It just wasn't them. Sure, they'd happily spend a night under the stairs, go camping on the beach or rendezvous in a cabin in the Canadian winter, but when it came to events like this it was all foreign.
Natasha thinks they should change that, as she sways to the music and decides it's not all that bad. Clint's holding her palm in his, other hand on her waist and their bodies so close she can feel his breath on her ear. She sneaks a glance upwards to see a smile gracing his face, and hopes that he really is the worst actor she knows, and that the smile is real, not just put there for his cover.
"I love you, Tasha." He whispers, and though she really should tell him off for using her real name whilst undercover, she can't bring herself to do it. Instead she whispers back.
"I love you too, детка." She opts for a pet name instead, thinking that at least one of them should pretend they actually cared about not compromising the assignment.
Later her takes her outside; their real mission was later, they only came here for appearance's sake.
They stand on the balcony overlooking the pool together, and he decides now is the time.
He doesn't get on one knee because he knows how much she'd hate that, but he does wait until she's turned to face him and their eyes meet.
"Natasha Romanoff" He begins, not planning to say many words because in this profession sentimentality doesn't mean that much, and to Natasha it means even less. She knows how much she means to him, anyway. "This isn't me declaring my undying love for you, or saying I hope we live long enough to grow old and grey together, because we both know that's not likely to happen. But it is this. I, Clint Barton, do promise to love you for every day that I am alive, wholeheartedly and in every way possible. I want to give you the stars, Natasha Romanoff, but in the meantime I hope you'll settle for just the Earth, and us upon it."
He doesn't want them to sound like vows but he uses their full names because he honestly doesn't know if they'll ever get the chance to do it properly, and he wants her to at least feel that this is special and real. She deserves that.
He doesn't ask the question, just silently holds out the ring, but she answers anyway.
"Okay." She lets out with a shaky breath.
"Okay Barton." Okay meaning yes, but not quite that because 'yes' sounds too formal and definite. And in their lives, nothing was definite.
He slides the ring on to her finger, and for the first time in as long as they can remember, they both feel happy.
He continues playing with the ring long after she falls asleep on his shoulder.
"I promised I'd always love you, and I'm promising now that I'll always come back to you."
He just hopes she starts to believe it.
The third time it happens, it doesn't happen at all.
She wasn't even supposed to be here with him, but after 5 months of only hearing him when he called, never seeing him, she couldn't take it anymore. She told Steve, Tony, Bruce and Thor she had a new mission with SHIELD, and told Fury, Coulson and Maria she was taking a holiday. Which wasn't a lie, technically.
She'd managed to sneak Clint's location whilst Fury attempted to sign her off duty for the next two weeks, eventually giving up with the computer and opting for just a paper copy instead. She smiled politely and thanked him, knowing he wouldn't be nearly as generous once she returned and he found out what she'd really been up to.
From there she boarded the plane, and touched down only a few miles away from Clint's last tracker reading. But of course he was never going to stay there for long, and it took her nearly the first week of her 'holiday' to find him.
Although her initial presence in his safe house did surprise him, he had already been expecting it for the past weeks. They both struggled when the other was away on a long-term mission, and more times than not they ended up subtly becoming part of the mission, unbeknownst to everyone around them. Only once had they been caught, when Clint forgot to deactivate his tracker before joining Natasha on her mission in Ukraine.
He listened as she told the lies she gave to come and be with him, and once again told her that he really was about to come home; he would never leave her behind.
As the second week was almost up, Clint was told his mission was successful and he was to await extraction. Normally Natasha would leave separately to Clint, either before or after on a different plane, so as not to arouse suspicions. This time however she decided she wanted to stay, consequences be damned when she returned with Clint on the SHIELD issue plane.
They packed up the safe house, and moved to their vantage point where they would soon be picked up. Except then a snow storm came in, and the agents had no choice but to huddle in a nearby cut-out of the mountain, offering little protection to the blizzard raging on outside. After the night had passed, he gently woke Natasha up, telling her he was just going to check to see if their plane had landed and that he'd be right back. He promised.
He'd obviously underestimated the effect that the cold weather had on his body, because just after he spotted the jet advancing towards him, he began to fall, his head landing rather heavily on the snow-laden rocky terrain.
When he woke in the SHIELD medical bay, his first thought went to Tasha. Coulson was standing at his side, and he demanded to know how long he'd been there, ignoring the pain in his head.
"3 weeks Barton. You've been out cold for 3 weeks."
No no no. This couldn't be happening.
"Tasha, where's Natasha?"
"She's fine Barton, just left for a holiday in the weeks before you were due to get back." He didn't mention the fact she should have been back 3 weeks ago.
"No she didn't, she was with me Phil, she was with me." He was beginning to panic now.
"A holiday? She told us you sent her on a mission." Clint hadn't even noticed Steve in the corner.
"I signed her off duty just over a month ago, she certainly hasn't been on any missions."
"But then where-"
"Would both of you just shut up?!" Clint cried, and the other two men turned their attention to him. The words come tumbling out. "You don't understand, she came to find me there and then we were ready to leave but I needed to check and she must have saw the plane leaving and oh god... she must have saw the plane leaving." He choked out. He turned to Coulson, his eyes full of so much desperation and despair he could barely hold his gaze. "She thought I was leaving her behind."
Three days later Steve and Tony return. "We found Natasha." Tony announced, but he wasn't smiling.
It used to amaze him each day, that despite what they'd been through, she still thinks he would leave her behind.
And now it breaks his heart, because he knows she sat there alone and cold with tears pouring down her face begging for Clint to return, all along thinking maybe she was right.