Colonel Roy Mustang had not been a submissive man; there was a part of him that had always been pained to bow his head to his superior officers and accept foolish, useless orders. When he became Fuhrer Roy Mustang, he had freed himself from all of that. He had no regrets for doing so. There was a difference between obedience and responsibilities; he preferred control over both. He locked the office door and returned home with his hands in his pockets, at ease.

He was startled to find Fullmetal in his home, but not terribly alarmed; Edward Elric had owned a key for five years, since he had been seventeen and angry and they'd made the mistake of fighting where nobody else could see. It was still not Fullmetal's home and he doubted it would ever be; Fullmetal was away too often, out on missions, out with his brother and his friend Winry. Nevertheless, Fullmetal seemed to have taken it as a good place to visit, and he had to admit he was amenable to that.

"Oh, hey," Fullmetal said, looking over. "I ate some of your leftovers."

Roy nodded, made plans to send someone for groceries soon. Fullmetal was devastating around food supplies. "That's fine." He walked over to the sofa Fullmetal was sitting on, draping his coat over the back, and looked at what was lying on the seat beside him. "Is that-"

"Eh?" Fullmetal blinked at him, then down at the leash. "Oh yeah. I stopped in at the office to hand my report in and Major Hawkeye asked me to walk the dog."

"And you somehow ended up with his leash?" Roy's tone was bemused.

Fullmetal shrugged. "He was running in the atrium and Havoc said he'd take over. I forgot it was tied to my belt. It happens."

"You'll return it tomorrow," Roy warned, and Fullmetal snorted at him, violently. They both knew what the Major's reaction would be if Fullmetal lost something of hers.

"You're looming," Fullmetal said after a moment, abruptly. "Sit down."

Roy did, an amused smirk quirking the corners of his lips. A comment on Fullmetal's height passed unspoken between them and Fullmetal glared. It had never stopped being entertaining, and as he'd let the obvious go, he couldn't resist the inobvious. "Still," he mused aloud, "I suppose it's only appropriate. A self-proclaimed dog of the military has brought himself a collar."

Fullmetal snorted again, glaring. "You're one to talk. At least I'm not an old dog."

Voice low, smirking, Roy hmmed at him. "Now, is that a way to talk to your master?"

He hadn't expected the response; in retrospect, he should have. Fullmetal was too similar to him in too many ways, likewise not a submissive man. Worse that he was forced to take Roy's orders, even if Roy was careful with them. To imply it carried through to other things was intolerable - the type of teasing Roy was given to, certainly, but intolerable. He would not have tolerated it, were it given to himself.

"What was that?" Fullmetal's voice was low, nearly a growl, and the leash was a garotted line of pain against Roy's throat. "What did you say, you shit?"

"Ah," Roy said, and there was regret in his voice. "We're a sad pair."

Fullmetal's eyes darkened and his grip loosened. "I shouldn't have come back here."

Roy considered this, shrugged minutely. "Perhaps," he allowed. "But you have." The silent question of whether it was a mistake hung in the air between them.

Fullmetal said nothing, simply tossed the leash down and looked away.

Roy picked it up.

"I won't be here long," Fullmetal said, harsh. "The Major says that you've got another mission lined up for me soon, because it'd kill you or something to let me take a break, so I've got to prepare for that. I just didn't want to book into a hotel."

"Yes," Roy agreed. The leather was soft in his hands, well-used, smelled faintly of animal sweat. "I suppose that would be irritating." He slid the collar around his throat, fastened it.

Cautious, Fullmetal muttered, "What are you doing?"

Roy exhaled, tightened the collar snugly, and handed the leash to Fullmetal. "Here," he said.

"What?" Fullmetal's lips had pulled back, nervous and a little angry.

"It's yours."

Staring at the leash in his hands, Fullmetal seemed not to know what to do or say. His fingers tightened after a moment, metal clenching, and he gazed at his own grip on it.

It was different when he chose to.

Fullmetal wound the leash around his hand, silent, eyes lowered to watch his fingers work, wound it tighter. It tugged; Roy followed it, letting Fullmetal reel him in until Fullmetal's cold knuckles touched his chin. He looked up, met Fullmetal's gaze.

"That's sick," Fullmetal exploded. "It's sick, you're sick-!" He let the leash unwind, struggled with the collar. Roy felt the back of his neck heat up at the rub, didn't move as Fullmetal undid it, threw it across the room where it hit a lamp and hung, precariously. "That's-"

"Sick?" Roy offered, amused.

Fullmetal's fingers, metal and flesh, were tight on his shoulders. He leaned close, almost panicked. "I don't want that."

"Neither do I," Roy said.

"Then why-" and Fullmetal realized, and he stopped.

There was a silence before Fullmetal sucked a breath and said, subdued, "I can't even stand you, you know."

"I know."

They made love on the couch as if it were too much energy to go elsewhere, used hands and mouths and after, Fullmetal met his eyes and dredged up a wry smile. "I'm tired," he said, as if it were explanation.

"Then sleep." Roy put a hand on the back of Fullmetal's head, pressed it to his shoulder.

"You too," Fullmetal ordered, voice vague. His hair draped over Roy's shoulder, cool as silk. Fullmetal shifted again to get comfortable, maneuvering both their bodies until he found a better place, then relaxed.

Fuhrer Roy Mustang slept.