This is my very first attempt at a Blackfrost fic! I've been dying to write one but never had an idea until this came up. Quick thank you to my best friend for pushing me to get this done and also to AlisonAPD who has been incredibly supportive and super nice. I hope you like it and please let me know what you thought.

Their affair had been going on for months now. Her friends knew she was with someone whenever she retired for the night early. At first they had simply wondered if she was fine, until Clint recognized the expression she wore on her face and her behavior the next day. Ever since he told them about the company, Tony had frequently asked her about it. He made it his mission to find out who the mystery lover was. He would ask whenever she left early, no matter how often she ignored him or threatened him. He knew no boundaries and Natasha had long grown used to it. Steve and Bruce both respected her too much to get involved in her personal matters and never bothered her about it. They tried telling Tony off the first few times but eventually left him to it, knowing it'd be a useless attempt anyway. And Clint simply knew better than to risk his health with a question. A few remarks passed his lips though but Natasha just grinned at him and slapped him over the head when she passed him. Thor, who was around more frequently lately, didn't dare ask. It was none of his business anyway.

Tonight was another night just like that. They all had had dinner together, the conversation flowing between them. Clint and Natasha were talking about their latest mission together and Thor went on about how things on Asgard were. Bruce and Tony discussed a few adjustments they had made within the tower while Steve just sat there, trying to listen to everyone. Thor had his main attention at the moment, the God happy to speak of his home to somebody. He barely even noticed that nobody else was listening to anything he said.

A good half an hour later, Natasha got up and excused herself for the night.

"Going already?" Tony asked, interrupting his conversation with Bruce, "Seriously, this mystery boyfriend of yours is getting more time than we do lately."

She rolled her eyes at him, a grin on her face though. He was impossibly childish sometimes.

"I told you, he's not my boyfriend. And you're just jealous because you're not the center of attention. You should spend more time with Pepper, Stark. It'd do you some good."

Clint chuckled when Tony pouted, taking a sip from his drink. He mumbled something rude under his breath and Natasha's grin widened.

"See you guys tomorrow."

They bid their goodnights and she left, amused. At least it was never boring at the Avenger's Tower.

It was better they didn't know who she spent her nights with. She was grateful that JARVIS never said a word to anybody about her guest. Thor would have a stroke and the others would make a mess trying to get rid of him.

She reached her room a couple of minutes later and got in, shutting the door close behind her. There wasn't much in here. She didn't spend a lot of time at the tower and she had grown used to living with as little furniture and luxury as possible. She didn't need much. Tony had been personally offended when she had told him she didn't need everything the others had in their rooms and he had insisted that some things stay. They had eventually reached a compromise they could both live with. The TV they had agreed on turned out to be the biggest flat screen possible and though she barely watched TV and found no particular interest in the item, she liked it. Clint had gotten her a few DVDs and it was rather nice to watch them on a big screen. Sadly, that also invited Tony to stop by more often and crash on her couch for a movie marathon.

Before she could even settle, she felt his cool presence behind her.

"You're late." He mumbled.

His breath was cold and it sent a shiver up her spine. He wrapped his arms around her middle when she didn't turn around and she smiled to herself.

"Sorry, Loki."

She felt his lips on her neck and closed her eyes, relaxing into the embrace. It hadn't been long since the last time they had been together but she had missed him. Not that she would tell him that, ever. Loki simply continued kissing her skin, obliviously to her train of thoughts.

"I must admit, I rather like these clothes." He mused, pulling back and spinning her around to look at her.

He liked her catsuit, of course. How couldn't he? It fit her body like a second skin and it made her incredibly irresistible. But seeing her in casual clothes, this little bit of normal life, just did things to him. The hoodie she wore was almost cute, if it weren't for those skin tight jeans and that leather jacket. Everything about her was perfect and he couldn't quite understand the effect she had on him. For once, he also wasn't trying to understand. It would only complicate things and he had no wish to ruin something so perfect.

Natasha arched into his touch when his hands wandered up to cup her breasts. She groaned and he smirked, one hand running back down to press her closer against him. She bit her lip at the look in his eyes, so dark, his pupils so dilated. Out of everyone she had ever been with, nobody had ever looked at her like that. Nobody had ever made her feel like Loki did right now. Her body was on fire already. She felt incredibly wanted and needy and so ready for him. Never had she anticipated being with anyone so much.

They stared at each other for a while until Loki closed the distance between them, kissing her hard and urgently. His own need was apparent when he walked her back against the wall and pressed his body against hers to trap her there. She ground her hips against his, biting his lip. Her arms went up around his neck so she could tug him down further. She needed more of him.

"I think you would prefer my clothes on the floor."

"You're right." He grinned.

Loki took that as a not so subtle hint to get her out of her clothes and he pulled back enough to tug her hoodie up over her head. It fell to the floor next to them and he kissed her neck down to her collarbone. Natasha leaned back against the wall and ran her fingers through his hair, gripping it painfully tight when he bit her breast. He pulled back when she whimpered, a smug and very satisfied grin on her face. He took a good minute just looking at her and she used the small break to catch her breath. How he could leave her breathless so easily was beyond her. She neither cared nor minded though. She liked it. He knew exactly what buttons to push.

Natasha leapt forward to kiss him again, trying to get his shirt off. At least he went for Midgardian fashion, it made things a lot easier than if he still wore his Asgardian armor. He had worn it the first time but never since. She was grateful for it. They never had the patience for all the laces and time it took to get the armor off. And she'd never accept it if he just magically made their clothes disappear. He had tried, she hadn't appreciated it.

The shirt joined hers on the floor and she bit his neck once she wasn't otherwise busy anymore. Loki moaned and his hand shot up to the back of her neck to keep her in place. He ground against her, steadying himself against the wall with his free arm. When she broke away from his skin again, she had left an obvious mark and she smirked at him.

He couldn't help but smile smugly at how small but fierce she was. He picked her up and Natasha wrapped her legs around him. Loki pushed her back against the wall once more. She ran her fingers through his hair, massaging his scalp absently.

"Do you want to move this?"

"God, no."

Neither had he wanted to. She always knew what he wanted. It was a blessing most of the time. Unless she decided to play with it and torture him by not giving him what he wanted. He kissed her again and she reached down to work on his pants. Her fingers brushed against his erection and he groaned. Natasha smiled sweetly and let go of him again. Loki reluctantly let her down. He liked it when she was wrapped around him like that but the look in her eyes now promised it would be worth it. And whatever doubts had remained vanished when she sunk onto her knees and pulled down his pants and underwear. She smirked up at him, reaching out to get a hold of his cock, stroking it steadily. He screwed his eyes shut when he felt her lips against him. She licked his entire length before wrapping her mouth around his cock.

He cussed, holding her head in place to thrust into her slowly. She was far too good at this. It was a shame that she hardly did that for him. He made her a few times but it wasn't quite the same. His hold became a little painful but she couldn't mind less. She liked it. It was the best indicator that she did it right and he liked it too. And that much was obvious by now. The fact that she could make him lose control like that in a heartbeat was only helping. She loved the power, over him especially.

Loki squirmed and tugged her away again a few minutes later. He wanted this to last for a little longer.

"Fuck, Natasha…" He whispered, breathless.

She smiled smugly. Once she stood again, she got rid of her bra as well as her pants and panties, teasingly slow. As soon as the last item of clothing hit the floor, Loki turned her around and she steadied herself against the wall. He ran his fingers down her spine, watching her shiver and whimpered in need. She was so perfect.

"Loki…"

He kissed her neck, licking a path up to her ear before he thrust into her. His hands held her hips in place and he took a moment for her to adjust. She braced herself, knowing what was to come next. He started moving again, his thrusts rough and hard. It was always like this, never gentle or loving or slow. It was one of the reasons he kept coming back. He didn't need to be nice or considerate. And neither did she. It made them work.

With the way he was slamming into her, she wouldn't need long. She was close already, worked up. Her body was trembling and she'd have troubles remaining upright soon. He smiled, rather happy to leave her a squirming and needy mess. One of his hands moved around to her front, from her breast down to her clit, adding pressure on the nerves until she groaned and whimpered.

His name left her lips when she came. He returned his hand to her hips, tightening his hold to the point it left bruises on her skin. He came a few thrusts later and dropped forward to rest against her, keeping his weight off of her.

They remained like that for a few minutes before he pulled away and tugged her to bed.

"Feeling cuddly tonight?" She chuckled.

"No. I'd just like to rest up a bit before leaving again. Somewhere comfortable."

"Good idea…"

They got to bed and stared up at the ceiling, lying next to each other. Loki turned to his side, watching her thoughtfully. She turned after another minute, looking right back at him.

"What's on your mind?"

He looked at her for a few seconds, pondering his reply.

"Why me? Why do you share your bed with me and not one of your little friends?"

Loki hated the question in itself but it had been on his mind for some time now and his curiosity had finally gotten the better of him. He needed to know. Natasha had to take a bit to think about her answer. The thought had never really crossed her mind before. He had simply been the perfect choice.

"Tony and Bruce have someone, they've always been out of the question. Same for Thor. Steve… Steve is a good man. Nice guy. He's too good for me. He deserves somebody nice. And Clint…He's like a lovesick puppy. He didn't give me a second chance because he thought I deserved one but because he fell for me. I'm not good with feelings and I care about him too much to fuck up our friendship."

"But why me?"

"And not some random stranger? It's you because you're perfect. You're fucked up, you're dangerous and you understand. You know what it's like to be where I am. Or was. Maybe both. You don't need me to cuddle after we slept together and you don't mind me not talking about my feelings or how my day went. Not to mention that you like taking control as much as you enjoy when I take it. I don't need to get what I want all the time and you know it. And I like it. I don't need flowers and dates and a happy relationship. This is perfect. Besides, you make my body react to you like nobody else has managed to in years. That's a good point for me to keep this up."

Loki listened carefully, smiling a little at the last part. He hadn't really known what to expect, what he had wanted her to say. But he liked her answer. He dipped his head in a silent thanks and then offered her another small smile. He was by no means shy but it was nice to be appreciated.

"Why did you come to me that night?" Natasha asked, her eyes fixed on the ceiling once more.

Now that he had brought up the topic, she couldn't help but be curious herself. He chuckled briefly, amused. She always needed to know everything.

"You're intriguing. For a mortal. As you pointed out, I know what's it like to be where you are. Which means that you can understand me better than most. At least for that. And I find myself attracted to you so I needed to have you."

"Simple enough." She laughed.

They fell silent, thinking about what had been said. They had talked about their relationship before, quickly deciding not to tell anybody about it and just go with it, wherever it would take them. He just showed up when he felt like it and they spent the night together before he'd disappear again.

"Natasha."

"Yes?"

"Do you love me?"

"Do you?"

He turned to look at her, smiling. They both knew the answer to that.

"No."

"No." She smiled.

He didn't love her. She didn't love him. It was perfect and it made them work.

They spent the next hour in silence, both smiling to themselves until Loki could hear the deep and even breathing coming from her. She had fallen asleep. He watched her for a minute or two before getting up and getting dressed. He left quickly, quietly. They would see each other again soon. And maybe, one day, it would be more than what it was.