"I'm sorry, Bucky. It's the only way I can keep you safe."

"Get to it then! I don't know how much longer I can hold on," Bucky sounded strained. He was using his right arm to keep his left one pressed tight against his body, but the mechanical arm struggled against him.

The trouble had started earlier that day, right after Bucky woke up. He had felt off, but he didn't know why until his left hand had suddenly grabbed Steve by the throat. They had called in the help of Tony and Bruce. Getting close enough to examine the arm themselves had been impossible, so they had decided to take Bucky to the repair bay on the top floor of the Tower. Tony had modified the software controlling the robots and they had scanned him. It hadn't taken long for them to locate the problem, but a solution would take them at least a day or two.

"First we need to find something to turn off the arm," Tony had explained. "Then, if that's done, we can fix the problem."

When they had been ready to leave the two scientists to their work, Bruce had taken Steve aside. "Be careful. The problem looks to be progressive. Right now he's only attacking people if they come too close, but he might start hurting himself. If he does," Bruce had paused for a second. "If he does, take him to the basement. He'll be safe there."

Steve hadn't forgotten his advice. He had gone to the basement to check out what Bruce had been talking about, but he had hoped they wouldn't need the room. When he caught Bucky struggling against his own hand wrapped around his throat, he knew that hope was futile. He had, with Bucky's help, managed to overpower the metal arm.

"Buck, we need to make sure that arm doesn't kill either of us before Banner and Stark can fix it." Steve had guided Bucky down to the basement, two hands holding on to his metal arm. "I wish there was something else I could do."

Bucky hadn't understood what Steve had been talking about until he had entered the room in the basement. He had taken hold of his metal arm so Steve could open the door. When Bucky had seen the chains attached to the wall, the arm began to struggle even harder.

"Are you sure this will even work?" Bucky asked.

Steve opened the manacles. "I think Banner uses them when he needs help controlling Hulk."

"Will those cuffs even fit tight enough around my arm then, if they're meant for Hulk?"

"Stark made them. They adjust to the size of the arm inside it. That way, Banner can lock himself in and doesn't have to worry about breaking free once he's changing."

Bucky nodded. He had tried to pay attention to Steve's explanation, but his arm was distracting him. "Hurry up!"

"I've got it, I've got it," Steve said. "Sit down and try to push your arm against the wall."

The chains attaching the manacles to the wall weren't long. Bucky knew he would end up with his arm raised in the air for quite some time. It reminded him of the way the girls in the Red Room would sleep every night. He took a deep breath and moved to where Steve had pointed. He lifted up his arm and heard the scrape as the manacle settled around the metal. He tentatively let go of his arm and, while it still struggled against its bond, the manacle held. He looked over to Steve, who had settled down on the floor, leaning against the wall opposite Bucky.

"What are you doing?"

Steve shrugged. "I thought I'd keep you company for a while."

Neither of them said much after that, until Steve noticed Bucky squirming a bit.

"Are you okay?" He come over and kneeled next to Bucky. "Are you in pain?"

Bucky shook his head, a slight blush on his cheeks. "I'm fine," he croaked out.

"Then why are you moving around like th – Oh." Steve had been running his eyes all over Bucky's body, trying to see if and where he was hurt, but then he noticed the bulge in Bucky's sweatpants.

"Yeah, oh." Bucky stopped squirming. "Maybe you should leave so I can take care of this?"

Steve nodded and moved away, only to stop and move closer again two seconds later. "Maybe I should stay?" he whispered. He leaned in so he could whisper into Bucky's ear. "Maybe I should watch you take care of it?" He settled a hand on Bucky's hip. "Or maybe I should take care of it for you?"

Bucky closed his eyes and moaned. When he opened his eyes again, he saw Steve's grinning face in front of him. He used his free hand to grab Steve's neck and pull him in, slanting his mouth across Steve's. Once he was sure Steve wouldn't back out, Bucky let go of his neck and moved his hand down to where he needed it the most. Suddenly his right arm was pushed up over his head. He felt something metal close around it. He broke off the kiss to look at his arm and found it secured against the wall in the same way as his metal arm was. He tried to glare at Steve, who was looking at him with a mischievous twinkle in his eyes.

"Don't look at me like that, Buck. I know you like it," Steve teased. "Looks like I'll have to take care of this for you," he said as he straddled him.

Steve slipped a hand past the elastic waistband of Bucky's pants and was not surprised to discover Bucky had chosen to go commando. He had known about Bucky's dislike for underwear ever since they were teenagers. He slid his hand lower until he could grasp Bucky's cock, pulling it free from its confines. He started off tugging slowly, occasionally speeding up, only to slow down again when Bucky's moans got louder. Bucky started moaning his name, trying to say something, so Steve slowed down again until he was hardly moving his hand at all.

"Steve, oh god, Steve." Bucky was panting, looking at Steve through half-closed eyelids. "Use me," he sighed. "Use my mouth. God, Steve, I want to taste you," he moaned, licking his lips.

Steve kissed him. He pushed his lips hard against Bucky's, taking Bucky's lower lip between his and gently biting down on it. One of Steve's hands sneaked under Bucky's shirt and slid all the way up to start playing with one of his nipples, while the other hand was still jerking Bucky's cock. He was going faster and faster, making Bucky moan into the kiss. Steve grinned against his mouth. He broke off the kiss to whisper into Bucky's ear.

"I want to see you come." He licked a stripe up Bucky's neck. "I'm going to make you come." He twisted his hand a bit as he kept jerking him off. "After you've come all over yourself, I'm going to fuck your filthy mouth." He lightly pinched his nipple. He moved his hand faster and faster.

Bucky's moans were louder and louder. His voice went up in pitch. His breathing became shallower. He clenched his right hand while his left arm was still wildly trashing about. He pinched his eyes shut as he leaned his head back against the wall, exposing his throat.

"Be good to me," Steve whispered against the skin of Bucky's jaw. He bit down softly on his Adam's apple as he gave Bucky's nipple one final pinch. "Come for me."

With a cry, Bucky came, spilling himself on his shirt and into his lap. Steve kept jerking him off, as pulse after pulse of seed landed on him or dribbled down over Steve's hand. "Please. Stop. Please. Too sensitive," he begged as he hung limply in his chains. He panted, trying to get his breathing and heartbeat back under control.

Steve showed Bucky some mercy and released his cock. He watched as it went soft again. He tucked it back inside the sweatpants and waited for Bucky to come back to the land of the living. As soon as he did, Steve lifted his hand up to Bucky's mouth.

"Lick."

Bucky followed Steve's order and hungrily began lapping at Steve's fingers, licking his own come off of them. He kept going until Steve's hand was completely clean again.

"Good job," Steve said as he lightly tapped Bucky's cheek with his now clean hand.

He stood up, feet still on either side of Bucky's legs, and pushed down his sweatpants and underwear. His cock bounced up when it was released. Bucky's moans of pleasure had made Steve hard. He started pulling on his cock, making himself even harder. He took a step forward and waited for Bucky to open his mouth. When he did, Steve used his hand to guide his cock inside.

"Yeah, that's good. Take it all," he encouraged Bucky as he held his head clamped between his hands.

Steve pushed his cock slowly further. When he was fully sheathed inside Bucky's mouth and throat, he held still for a few seconds. He felt him try to moan around his cock. He saw Bucky's eyes widen and pulled back until the head of his cock was resting against Bucky's lips. He allowed him to breathe in and out a few times, and then pushed back in. He looked down and saw Bucky's lips stretched wide around his cock. He used his thumb to trace Bucky's upper lip.

"So beautiful," he said as he pulled back out.

He let Bucky breathe for a minute and then pushed back in, not as far as before. He held Bucky's head tight between his hands.

"I'm going to fuck your mouth," he said as he thrusted his hips forward once. "I'm going to come down your throat." Twice. "You're going to swallow everything I give you." And again.

Steve kept thrusting in and out as Bucky gave Steve total control over him. He looked down at Bucky and saw the trust shining through in his eyes. It didn't take long before Steve could feel himself getting close. He slowed down his thrusts, making them more shallow. He managed to teeter on the edge for a little while, until Bucky started humming and sucking. The added sensations made Steve fall over the edge. He shot his load inside Bucky's mouth, coating his tongue and throat with come. Bucky swallowed around his cock. It felt heavenly to Steve. He released Bucky from the tight grip he had on his head. He tugged a few times on his cock, emptying himself fully inside Bucky's mouth and then pulled back.

"Clean me up," he said as he slid his hand in Bucky's hair and gripped it tight.

Bucky cleaned the rest of the come from Steve's cock and swallowed it. He started sucking again, but Steve pulled away until he was out of Bucky's reach. He tucked himself away, pulling up his underwear and sweats. When he was fully dressed again, he released Bucky's right hand from its manacle and it dropped down into his lap.

"Are you okay?"

Bucky hummed in reply. He was exhausted. He closed his eyes and leaned his head against the wall. His left arm was still moving around, but Bucky was no longer in pain from losing control over it. He felt Steve cover him with a blanket he had stashed in a corner of the room before he took Bucky down here. "Sleep. I'll be back to check on you later," Bucky heard Steve say. He felt him caress his hair and press a kiss against his forehead. A short time later, the doors to the elevator opened and closed, but Bucky didn't hear. He was already asleep.