A/N: Well, my first FMA fic. Blame my friend for introducing me to the anime. I love it so much now.
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"Oh!" Landing flat on his back on the bed, Roy Mustang drew in a deep breath, recovering from the accidental strike of an automail elbow under his ribs. "Watch it, chibi!"
He almost felt the heat of Ed's anger radiate as the tirade began. "Who are you calling so small he can't control his own arms and-"
Roy deftly cut him off, occupying his mouth with a much more fun activity than yelling. Years with the younger alchemist had taught him that even in full flow, Edward Elric's rants could be restrained. All it took was a little... persuasion.
It was lucky that he had been jumped as soon as he came in the door, he reflected as he carefully rolled them both over, pinning Ed beneath him. Ed couldn't have been home long before him, as the blond was still fully dressed. That was convenient – this wouldn't work as well otherwise. Surreptitiously, he moved his left hand across Ed's body and touched it against the back of his right glove.
Ed was expecting the hands that crept up his stomach seconds later. But he wasn't expecting the very strange sensation that followed. Golden eyes snapping open, he frowned up at Roy, only to be greeted by a smirk. Eyes widening in worry, he pushed the older man off, ignoring his protests, and bolted across the room to the mirror.
For several long moments, he was silent in shock. When he spoke, his voice was hoarse. "Colonel Bastard, you are going to die for this."
"You don't like it?" Roy was stretched out on the bed, watching him with an expression of mock innocence.
Lost for words, the younger man could only splutter incoherently for a while. "Well, duh!" As he shifted in front of the mirror, his metal leg glinted, now bare from mid-calf, where his boot ended, to mid-thigh, where the rather unexpected red skirt reached its lacy hem. And the skirt, with the black and white layers underneath bulking it out, was only half the horror. The other half belonged to the tight black leather bodice and wristbands, the puffy red sleeves, and the white-ribboned black headband that lay over his hair. "How did you do this, you pervert?"
Roy simply grinned at him, waving one gloved hand. "I just transmuted your clothes. Once I had the picture in my head, it was like taking candy from... well... you."
For once, Ed didn't explode at the implication, but continued to stare at his new outfit. "...I knew you were twisted, Mustang, but this tops it all off."
"Tut tut." Stretching casually, the dark-haired man stood up and strolled over, stopping just behind the blond and looking over his shoulder into the mirror. "You haven't even seen my favourite part yet."
The look of consternation on Ed's face suddenly gave way to barely-veiled panic. "Should I even ask?"
"Allow me to demonstrate..." Roy's fingers crept up his back, and suddenly Ed felt a tug around his neck. Frowning again, he followed the direction of the tug, turning around to face his older lover. His eyes travelled from Roy's outstretched hand to the cord he was holding, and along the cord until it disappeared in front of his face. That was when he realised that the gentle constriction around his throat was a collar.
He swallowed hard. "Taking that 'dog of the military' thing a bit literally, aren't you?"
The answer was a wicked grin as Roy pulled him closer with the lead, carrying on until Ed was pressed right up against him. "Call it an alchemic experiment, Fullmetal."