BIRTHDAY QUICK FIC 2024: December 3-Natasha Romanoff (MCU)

Fandom: MCU/Harry Potter crossover

Summary: Two weeks after Natasha starts dating her fellow SHIELD agent, Harry Potter gives her a birthday present she’ll treasure forever. (Harry/Natasha)

Content Warnings/Themes: Crossover, AU, gen, no sex

This wasn’t what I had planned for Natasha’s birthday fic, but it just sort of happened.

“Happy birthday.”

Natasha Romanoff was not often struck speechless, but Harry Potter, her fellow SHIELD agent and the man who she had started dating a couple of weeks earlier, seemed to have a knack for catching her by surprise. Whatever she’d been expecting him to say as he held her hand and leaned in to whisper into her ear, it wasn’t that. She’d sort of figured he was going to suggest that they go to bed for the first time. If he had, she probably would have been on board. In fact, she’d come into this date thinking that if he didn’t make the move, she probably would. Going on dates was a new development for her and the wizard she’d recruited into SHIELD more than a year earlier, but their mutual sexual attraction dated back months. Natasha had been thinking about hooking up with Harry Potter well before he’d asked her out for the first time, and she’d been prepared to act on those thoughts tonight. But what he’d just whispered into her ear completely derailed her thoughts of finally finding out what those gorgeous green eyes of his looked like when aroused, at least for the moment.

“Thank you,” she said slowly, responding to him after recovering from her initial surprise. “So, I guess you got your hands on my file?”

“What do you mean?” Harry asked, looking at her blankly. Natasha had known him and worked with him enough to be able to see through his lies with barely a glance. He wasn’t a great liar to begin with, and she was an expert at both deceiving people and recognizing when they attempted to deceive her. She saw nothing that betrayed a lie now, which had to mean that he was being truthful.

“December 3rd is listed as my birthday in my file at SHIELD,” she said. “I figured that was where you got it from. Not like I go around offering up personal details about myself, unless there’s a reason behind it.” She shrugged.

“No.” Harry shook his head. “I didn’t look at your file. The date on your birth certificate didn’t matter. What mattered was whether or not you celebrated the day with the people you care about.”

“But I haven't celebrated my birthday in years," Natasha said. Now, he was confusing her. "I don't even remember the last time I celebrated it, actually. It probably wasn't since…" She trailed off, looking away as her mind flashed back to the last period of her life when she'd been able to cling to the idea of normalcy.

“Since you were a child, living in Ohio?” Harry finished for her. Natasha nodded, keeping her face impassive while she swallowed back the emotions. She trusted this man more than most, but she did not like feeling as vulnerable as those memories made her, not around anyone. That he knew about her three years in Ohio was in itself a symbol of how much she trusted him. Harry was only the second person in SHIELD who she’d told about those days, after Clint.

“Right,” she said. “It was all fake, of course. But for a few years there, I played out the idea of being a normal kid, with a father, a mother, and a little sister.”

“It wasn’t fake,” Harry said, shaking his head and staring at her, oddly intense. “Don’t tell me it was fake.”

“But it was,” she insisted. “It was all a charade. Just a charade so Alexei and Melina could get the data from the North Institute.”

“You were put there as part of a mission,” Harry agreed. “But the feelings were real, weren’t they?”

“Maybe I convinced myself they were, as a 7-year-old kid who’d been sold to the Red Room by my actual mother when I was an infant,” Natasha said, smirking ironically. “But none of it was real. We took our pictures for Christmas, Thanksgiving, Easter and our summer vacations all in the same day. It was all a show.”

“Your birthday wasn’t a show.” Natasha flinched and whirled around in her chair at a new voice speaking from behind her. How had someone managed to sneak up and get that close to her without her noticing their presence? Was she really that distracted, or was the sneaker a master of stealth herself?

She stared at the blonde-haired woman in confusion for several seconds. Even with her hands visible and no weapon in sight, Natasha could immediately sense the threat that this woman could pose as an enemy. That wasn’t why Natasha stared so hard at her, though. She was a stranger, and yet something about her felt instantly familiar to Natasha. She squinted, and her eyes widened as she pictured hair that same shade of blonde on a little girl she’d once called sister.

“Yelena?” she whispered cautiously while standing from her seat at Harry’s table and turning to face her. The blonde nodded at once, showing that Natasha's conclusion had been correct. It made no sense. What was Yelena doing here? Natasha hadn't seen her since they'd been separated at the Red Room when she was still a little girl. She’d taken Dreykov and the Red Room down with Clint’s help, but she’d never heard from her fake family again.

“Hello, Natasha," Yelena greeted her. Natasha was surprised at how fast her heart was beating. Yes, she'd feared for Yelena for years and hoped that she was okay. But they'd been little girls then, little girls who'd clung to a fantasy. Seeing Yelena alive and in front of her all these years later should not have had any effect on her. It couldn’t have any effect on her because it had never been real.

“What are you doing here?” Natasha asked. There were a million questions she could have asked, but that was the most obvious one in her mind. Questions like how did you survive and where did you go after the end of the Red Room were less important to Natasha than what she was doing standing there in Harry Potter’s apartment.

“Harry invited me,” Yelena said, hugging her arms around her body and biting her lower lip. “And saved me.” Natasha turned her head to look at Harry, who gave her a slight smile.

“That’s a long story,” he said, “one that I’ll be happy to tell another time, with Yelena’s help. But as to what Yelena is doing here? As she said, I invited her. She’s the one who told me when your birthday was.”

“I would never forget it, sister,” Yelena said seriously.

“We’re not sisters, Yelena,” Natasha said, shaking her head. “We never were. It was never real.” Unbidden, an image popped into her head of pointing a gun at the soldiers trying to take them to the Red Room, and little Yelena, no more than six or seven years old by the end of their time as a ‘family’, clinging to her, terrified. She squeezed her eyes shut to try and blink it, and the feelings that accompanied it, away. But with Yelena still standing there staring at her when she opened her eyes back up, the old feelings and dreams of a young girl who longed for a family lingered.

“Don’t say that,” Yelena said. “It was real. It was real to me. You were my sister. You were my sister, and I loved you.” Tears swam in her green eyes, and even though Yelena had gone through the Red Room just like she had, Natasha didn’t believe the tears were fake. If they were, Yelena had taken to her training in the Red Room far better than Natasha had. Natasha had spent her whole life tricking people and lying to people, but not even she could have put this much raw emotion into any performance.

“Yelena," Natasha said softly, feeling as lost as Yelena looked. The adult Natasha Romanoff was at war with the little girl who'd wanted to open the empty boxes under the Christmas tree just to make the lie feel real. Looking at Yelena and seeing her wipe tears out of her eyes with the back of her hand, Natasha felt stricken. When they'd been assigned to live with Alexei and Melina as part of their mission, Natasha had been old enough to know that it was all a ruse, even if she'd still loved them like they were her actual family. But for Yelena, several years younger than her, it had been real. As far as she’d known, Natasha had genuinely been her big sister, and Alexei and Melina her actual parents. Having their fake family torn apart had been traumatizing for Natasha, but it had to have been even worse for Yelena.

“You were my sister,” Yelena whispered thickly, shaking her head. “You are my sister.” She grabbed Natasha’s hands in hers. “Why do you think I still remember your birthday, even after all these years? Did we take pictures of me kissing your cheek, wishing you a happy birthday and calling you the best big sister in the whole world?”

"No." Natasha's voice shook at the memory, which she'd buried somewhere deep down, deep enough that she'd been able to spend years pretending that she hadn't loved Yelena as deeply as any girl had ever loved her little sister.

“Because that was real,” Yelena said. She didn’t bother trying to blink back the tears now. Natasha watched them drip down her cheeks, and if Yelena hadn’t been holding her hands, she just might have wiped them away herself. “I don’t care what you say, Natasha. You’re my sister, and I love you. Happy birthday.”

The child who yearned for her family had already won the battle, and when Yelena’s lips pressed against her cheek for a birthday kiss just like they had when they were kids, Natasha pulled her hands out of Yelena’s and engulfed her in a tight hug instead. So what if the presents had been fake, and their family had only been assembled for a mission? The feelings were real. Yelena was her sister, and now she had her back.

“Sister,” Natasha whispered. She pulled Yelena’s head down and let her sob into her shoulder while they hugged. As they turned, she saw Harry standing by the table, watching with a smile on his face. Natasha smiled back at her coworker, who she'd been dating for all of two weeks. That she'd even let him get this far was a testament to her trust in him, but she'd never expected it to become anything beyond some fun dates and potentially casual sex. She'd never allowed anyone to get closer to her than that, and until today, she hadn't planned on that ever changing. But that was before Harry Potter brought her sister back into her life, somehow, some way. There were still a bunch of questions that needed to be answered about all of this, but as she held Yelena tightly in her arms and looked at the man who'd made this unlikely family reunion possible, she was certain of one thing.

I’m going to marry this man.