Bruce Banner woke up on a Saturday morning, feeling completely refreshed, better than he had in ages, and with a warm body next to him.

For a few disorienting seconds he stared at the canopy above his bed, unable to figure out where he was. Years on the run had conditioned him to be ready to move at an instants notice and he was used to waking up in all sorts of places, few of which were indoors. Before he had settled in India, it hadn't been unusual for him to spend the night in a different village or city for weeks at a time, trading his medical skills for a night's food and lodging in whatever place he happened to be. If those options weren't available, he could usually find a tree or barn or bridge or even an abandoned house to make do.

None of those places however specialized in air-conditioning and high thread count sheets. After years spent on the run, it was a disorienting experience for him.

He relaxed as the memories came flooding back to him. He was safe in Stark tower and the warm body next to him was Natasha.

He rolled over, careful not to disturb her. Natasha slept like a cat, ready to wake at the smallest sign of danger. Banner could relate. He had spent most of his time on the run under similar straits. Natasha couldn't be used to the safety and security of Stark tower any more than he was.

She was still asleep, which was unusual. Most mornings as soon as he woke up, so did she, unless she was really tired. And most likely bearing some kind of injury that she needed to recover from.

He propped himself up on one elbow and gently brushed her hair away from her face, grimacing as his questing fingers uncovered a bruise on the side of her face. It wasn't unusual for her to come home sporting cuts, burns and bruises, and those were injuries that she classified as mild. She had had worse ones that he knew of, and that was just in the time that he had known her. He had patched her up more times than he cared to count, carefully applying stitches over numerous cuts and abrasions as she lay in the bathtub, the water slowly turning pink with her blood. It wasn't unusual for him to be summoned to the SHIELD medical center to dig bullet fragments out of her because she was having one of her episodes and refused to take anesthetic or to let someone else touch her. The fact that Natasha's genetic enhancements allowed her to heal faster than most humans and that SHIELD had top of the line medical policy did nothing to soothe his unease.

He was never comfortable with this aspect of her job, but he kept it to himself. Natasha already had enough burdens of her own without having to deal with his insecurities. Even though she insisted that she was always there for him for whatever he needed, it wasn't fair for Bruce to load his burdens onto her, when he could do so little to lighten hers. Bruce had complete faith in her abilities, knew better than most that she was more than capable of looking after herself. It didn't make the protective feelings go away. A few decades of gender equality couldn't completely override thousands of years of evolutionary caveman instinct. He worried about her, and Natasha knew that he worried. She tried to placate his fears best as she could, whispering soft, comforting words in English and Russian as they lay together in bed, his arms wrapped around her and her nose pressed against his shoulder, their legs thoughtlessly entangled. It wasn't altogether the safest position for her to be sleeping in. Having his legs tangled around hers, his arm wrapped around her, could cost her at least a couple of precious seconds if some unidentified threat managed to make its way into their bedroom. But Bruce found it to be a source of comfort and so Natasha went against her instincts to let down her guard, and put faith in Stark and his security system to safeguard her and the most important person in her life until morning, when she could resume her vigil.

Bruce in turn suppressed his own overprotective feelings best as he could, even though the thought of someone, anyone, laying hand on Natasha, his Natasha set his teeth on edge. The very thought of Natasha being hurt made him see green around the edges. He wished he could protect her in some way, although if the time came it was more likely to be the other way around. He couldn't protect her in the field. Not as Bruce banner anyway. The Hulk was a different story of course. For a moment he almost resented his alter ego for being able to look after her in ways that he never could. But then again, SHIELD didn't allow one of their strongest and most unpredictable assets into the field unless there was an urgent and pressing need. He had gone along with them on a few of those missions, where the parameters weren't more complicated than to smash everything in sight. But those weren't usually the missions where he got to see Natasha. She specialized in a different kind of skill set, one that required a subtlety that the Other Guy noticeably lacked.

And so he stayed behind, to worry and fret over her, and wait for the inevitable day when some anonymous SHIELD agent wearing a black suit and a somber expression would arrive on his doorstep and give him the standard company line. I'm sorry to inform you that…

He shook his head, ridding himself of that thought before it reached its horrible conclusion, though in his secret heart of hearts, he knew it was only a matter of time. People like Natasha didn't usually live long enough to retire and take desk jobs. Natasha was strong, stronger than most, and damn good at what she did, but she wasn't the only one. At her level, skills weren't galactic leaps apart. She had beaten the odds so far, but one of these days, maybe tomorrow, maybe next year, maybe ten years from now, she would go up against someone who was stronger, better, or just plain luckier than her, and when she did, the law of averages would catch up to her at last. And when that day came Bruce would be the one who would be left behind to speak at her funeral, assuming there even was one, and mourn the loss of yet another person that he loved.

"You know, it's rude to stare."

Natasha's voice broke the silence abruptly, yanking Bruce out of his musings. He focused on her face to find her looking at him sleepily, eyes half open and that tender lopsided smile on her lips that she reserved just for him.

"Hi, baby," Bruce said tenderly, leaning over to give her a kiss. "How're you feeling?"

"Mmm…better, much better," Natasha said with a contended smile, twisting around and stretching in a way that did interesting things to her shirt. "What time is it?"

Bruce glanced at the wall clock. "It's almost seven. What time did you get back last night?"

"Not soon enough," Natasha said simply, closing her eyes and snuggling closer to him, one arm wrapped loosely around his neck, her legs tangled with his. "I'm sorry I missed dinner," she said sleepily.

"It's okay, hon," Bruce said softly planting another kiss on her mouth. "We have the whole weekend to ourselves." Natasha hummed in approval, a sound that made Bruce's heart melt, and drifted back to sleep, still snuggled up against his shoulder.

Bruce looked at her tenderly as his hand continued to comb through her fiery hair, sorting out the tangles. He liked running his hand through her smooth, silky hair, feeling it slide between his fingers like silk. He shifted on his elbow and settled in a comfortable position as he continued to stroke her hair. He liked watching her sleep. He didn't often get the chance and he savored every second of it. For a brief time, all the worries, cares and responsibilities of the world slid away from her face, and left her looking peaceful and vulnerable in ways that made him want to gather her in his arms and never let go. He wished that he could capture this moment, safe, warm and perfect, and hold it for ever. But sooner or later, usually sooner than later, the real world would come knocking. It always did.

He couldn't protect her from the dangers of the world it was true, and he was just going to have to make his peace with that. It was the cost of falling in love with someone like Natasha, and if that was the price he had to pay, he would bear it with no regrets. She was worth it. But while she was in his care, he would do his utmost to see that she was safe, cared for and loved.

And for people like them, that would just have to be enough.