Roy Mustang is never quite sure why he lets Full Metal take control from him.

It's odd, he thinks, tonguing the line of his throat, nipping at soft flesh. It's odd.

He prefers women, though he enjoys it either way. Women are easier, in a way. Whatever the military's unwritten policies might be towards men, there are no uncomfortable questions with women, no prejudice, no rumours reaching the ears of those who might review his next promotion. He knows it's said that he'd do anything to get a promotion, and while he wouldn't say 'anything', it's true enough. Women are easier than men, much easier than young men, far easier than young men under his command.

And everyone is easier than Edward Elric.

He hears himself make a noise in the back of his throat as Edward bites down on an earlobe. He can feel the grin through the lips against him, finds his lips curving in response. They've stopped talking; it's easier not to talk. He slides a hand down Edward's stomach, teasing, receives a shuddered exhalation as a gift as he continues, takes hold, pumps.

Edward's old enough for military service this year, but he wasn't the year before. Roy Mustang knows this, and knows that everyone else knows it. Rumours are one thing; there are always rumours. But if there is ever any evidence that he was abusing his command-

It is a bad idea, it has always been a bad idea. Sometimes, that matters.

Edward pushes at his shoulder and Roy turns over, rests his forehead on the mattress, lets out a shuddering sigh. Edward kisses each knob of his spine, lets teeth graze, slow, steady, as if there's a rhythm to that, a pattern that must be obeyed. Edward makes love as if it's alchemy, but Edward's form of alchemy - he violates all the rules, he always has. He doesn't need an alchemy symbol, just both hands and intent.

He shivers at the feeling of Edward's hands, one hot, one cold, both burning against his hips. He reaches behind him, catches Edward's hair, drags him close for a kiss, all wet hot mouths and tongues and teeth, and God-

Maybe it's the danger, but Roy doesn't believe it. He's good faced with danger, strong under pressure, knows the difference between what he can directly control and what he must simply rely on human nature for.

Perhaps it's the thrill of letting go - but, ah, Roy doesn't believe it, doesn't believe it as Edward presses against him, into him, doesn't believe it. Yes, he fears it, yes, it thrills him - but no, he's not good at it. Pushing back, he close his mouth on noises, keeps his eyes closed, keeps his face calm, moves. He doesn't open his mouth to tell Edward that his automail arm is too heavy on his right shoulder. He doesn't dare open his mouth.

He thinks it must be fire.

Edward's mouth is on the nape of his neck, licking and biting, and he moves hard, fast, picking up a rhythm and keeping on at it, keeping on at it.

Edward's braid is shifting against his left shoulder like a live snake, lightly; Roy feels the movement strongly, too strongly; he can't explain how strongly he feels it, he never opens his mouth to try.

The mattress is making noises and Roy listens to them, listens to the rasp of breath in his own throat, laboured, listens to Edward's harsh noises, listens to skin on skin and -

- and he thinks it must be fire, it must be fire, he knows fire, it's always known him, fire in his blood, curling inside him; it destroys and nurtures, it creates, it tempers, it-

Roy Mustang's eyes are closed as he comes, biting off a noise before it can form, leaning back into Edward, and at that moment he knows everything he needs to know.

*

Ed never wonders why the Colonel gives up control at times like this. He rarely thinks at all at times like these. He's too busy experiencing; that's how it takes him.

Lines and curves.

The Colonel's back is arched under him, a perfect curve. His hand, tracing it.

Breath, patterns in the air. Move. There's a goal here. His other leg, too cold; he spreads them slightly for a better grip and to keep his one leg from touching the other. Move.

The Colonel's head's down, he sees lines and curves, the nape of his neck, the line of his jaw, straight hair, an ear. He wants to touch it all but his hands and legs are occupied; he lets it go.

Heat. Movement. He's being distilled, shuddering; there's nothing left but what's left. Move.

A clench - he cries out, low, as the Colonel shudders. This - yes. He speeds up, moves, moves. Closer. Reaches for it, reaching, change, fire washing over him, held tight, falling.

He relaxes, hears his breath sigh free, pulls out.

As the Colonel wraps an arm around him, there's a smug and satisfied smirk on his face. Ed would get angry at any other time, but the anger's just not there right now, because he knows.

He knows.