While their sexual preferences mostly led them in other directions, sure, Clint and Natasha fucked sometimes. They always had, whenever they were both free, whether from need on the part of one or the other of them for comfort or release, or just because they were bored. But as their partnership solidified, their assignations took on a different character because they needed more ways to stay in balance. Natasha, who'd been involved in kink scenes here and there for some years, needed a safe place where she wasn't making all the decisions, and she didn't trust anyone the way she trusted Clint. For his part, while he didn't mind her being bossy, he wasn't her sub, and there was a difference.
The scenario was always the same, always in the tiny Washington Heights studio apartment they used as a hideaway, a space that belonged equally to both of them. Clint wore soft trousers, a shirt, the boots that Natasha bought him a few years back. He made sure there was plenty of water, that Natasha's robe was within reach in case she needed it, and that the space was warm enough. He turned off the bright overhead light and clicked on the lamps, brought the chair into the middle of the room. Natasha emerged from the bathroom a few minutes later clad in a full skirt and a cotton tank top.
"You ready?" he asked, and at her nod said "Come here, then."
She sat in his lap, flipping up her skirt so her bare behind rested on his thighs, and kissed him. Her waist was warm and tiny in his hands, but he wanted more of her softness, so he slid the tank top off her shoulders and began to run his hands across her breasts. His touch was selfish, rather than gentle, but then, gentleness wasn't what this was about. Still, she arched into his hands, her knees squeezing his upper thighs where she straddled his legs in the chair.
"Like that?" he asked, smirking.
"I like that you like it," she replied.
He raised his eyebrows. "You should get your tits out more often."
"Don't press your luck."
Clint grinned at that, then reached around and smacked her behind. "All right, assume the position."
Natasha stood and took off her clothes, then lay across Clint's lap. "All right," she said.
He reached down next to him for the belt and began to whip her ass with it. He didn't strike very hard, but it was a belt, so this was not a soft thing. He got a rhythm going, the blows and the way her body moved with them—away from it but back into the next one—was like a wave, like they were two bodies of water coming together. They didn't count; just paid careful attention. If she wanted him to stop, or keep going if he'd stopped, she said so. Most of the time, he got very, very hard, and she came, right there on his lap. He knew her tells, knew when the orgasm was coming, and would drop the belt and slip his fingers between her legs to help her along. And it was all incredibly hot, the stripes on her backside and her soaking wet pussy.
Natasha would take a second to compose herself, and then she'd climb off his lap and kneel between his legs, get out his cock and suck him off. It was then that Clint could look at her face, at her flushed, tear-stained cheeks and bright blue-green eyes, bitten-red lips stretched around his cock. It was no wonder he never lasted long.
After, they'd lay down on the little bed, cuddle, talk about things. It was easier, now, to work out what things were important and what things weren't, even for Clint who wasn't always paying attention to how he felt about anything. Sometimes they'd sleep, or order in, or watch a movie or a ball game. And the next day, they'd feel more settled, back in a good place with each other.
The way Natasha talked about Pepper Potts, after her op at Stark Industries, it surprised Clint not at all that she asked Pepper out, or that Pepper said yes, or that they continued to date for some months after that. (Clint had spent that time mostly in the rain in New Mexico; what the heck, Coulson?)
What did surprise him was Natasha saying that now that things were getting serious between her and Pepper, she probably should be there when Natasha and Clint did "our thing." (They didn't like elaborate names for things, okay? They had enough aliases to keep track of.) What surprised him even more was that he agreed with her, that it didn't even seem weird to invite Pepper to come into their space, watch what they did.
Of course Natasha hadn't set aside her kinks entirely when she became involved with Pepper. She tied Pepper up, used a whip on her sometimes, often enough that after she told Pepper about "our thing" she immediately knew how she wanted to participate, next time: she wanted to whip Natasha's breasts, with a little cat o'nine tails, while she sat in Clint's lap. And so, as she'd done with Clint, Natasha taught Pepper how to use her chosen implement.
It was hotter than Clint would have thought, having Natasha wriggling on his lap while Pepper whipped her. Her breasts were sore and throbbing when she lay across his lap, making her ready to come all the faster under his belt. When he looked down at her, his cock in her mouth, her breasts were red and tender. Plus he had another wet and willing pussy to slide his fingers into, when he got Pepper off while Natasha watched. They got a bigger bed for the back room so they could all fit, piled atop each other, and it helped bring Pepper in. Clint and Natasha only had each other to rely on for so long, so it was good to have someone else there. He was happy for Natasha, really. He just was ready to get some of his own.
Natasha would say later that the Coulson thing—the Phil thing, now—was also only a matter of time, that the fact that they both thought that the other deserved better meant that they absolutely deserved each other, but it didn't feel that way to Clint at the time. He'd been interested in Phil and not doing anything about it for quite a while but it was only after Phil didn't really die that Natasha lost her patience and goaded them both into it. Which Clint was thankful for, of course.
Phil's reaction to "our thing" was that he wanted to observe before deciding how to participate. Luckily he was already friends with Pepper, which made everything much less awkward than it might have been. And after watching, and touching, and all of them getting Phil off because it didn't seem fair if he didn't, they made their way to the bed.
"Well?" Clint asked.
Phil hummed, and then said, "Has anyone ever whipped you, Clint?"
"Natasha did, once," he replied. "But it was weird. I don't think we work that way."
"No," Natasha said, agreeing.
"What if I did it?" Phil asked. "I couldn't help but think, watching you, how interesting it would be if you were sitting on a very sore behind while Natasha wiggled on top of you. Don't you think?"
Clint blinked; he hadn't thought of that, at all. "Yes," he said. "I think it would be."
"I do, too," Pepper said.
"I can show you how," Natasha said.
"Thank you," Phil replied, and snuggled in closer to Clint.
It really was like something falling into place, like they'd been waiting for Phil and Pepper to come and balance them out, make it work even better. Make it change, but in a mostly good way.
"Then that's what we'll do," Clint said.