steve/bucky/nat, domme natasha
"Look at my good boys," Natasha crooned. "Look at how well you follow my orders."
Steve whined low in his throat, the muscles in his back taut from the strain of keeping still. His cock was buried up to the hilt in Bucky's ass, his fingers digging into his hips, but Natasha had told him not to move, so he wasn't.
She moved in closer, running her fingers lightly across Steve's sweaty shoulder. "Do you want to come, Steve?" He nodded wordlessly, earning a swift, open-handed slap to his shoulderblade. "Answer me," she commanded.
"Yes, mistress, please let me come!"
Natasha hummed happily, then leaned down to Bucky. She traced the shell of his ear with her tongue, earning a shudder. "James, darling, do you think Steve deserves to come?"
She watched his throat work as he swallowed hard, trying to sort through the haze of arousal for the answer she wanted. They would have to work on that, she decided. "You're in charge, mistress," he mumbled.
"Close enough," she whispered. She straightened and covered Steve's hand with her own, lacing their fingers together over Bucky's hips. "Come for me now, boys. Come now!"
She watched as the muscles in Steve's stomach and back tighten as he thrust into Bucky, and the way Bucky crumpled into the bed under the weight of his orgasm. Natasha smiled, petting Steve's shoulder as he rode out his own climax. "Good boys," she murmured. "So good."