It takes two to tango, after all.

Context: I really just wanted to write a dance scene because I'm trash, imagine the Jealousy Tango or La Cumparasita. Imagine this takes place sometime a year or two or three after the Promised Day incident, and Roy has his eyes back because otherwise this wouldn't have worked at all whatsoever. Enjoy this freshly baked fanfiction.

The heat of the ballroom was near overwhelming, and as Roy slipped through the tight crowd of high-ranking officials, a tiny bubbling drink in each hand, he decided that perhaps a full black tuxedo had been a mistake. As he made his way across the ballroom, sidestepping inebriated generals in tight suits and laughing women in silver and black gowns, he finally managed to approach Riza Hawkeye, who stood alone against a marble pillar, her blood-red dress standing out starkly against the white stone.
He offered her a breathless grin as an apology for his tardiness and handed her the small glass of alcohol. She responded with an inquisitive look.
'Roy, I told you not to bother getting this, I don't-'
'I know you don't drink,' he finished, sipping his own drink. 'But it's mostly for looks. That's what all of this is, after all- one big show.' He made a sweeping hand motion towards the generals and nobles parading around the ballroom and then somehow managed to look elegant as he drank from the tiny glass.
'I guarantee you aren't missing out,' he informed her. She raised a perfect eyebrow, and he added in a conspiratorial whisper, 'They went cheap this year.'
'They aren't the only ones who went cheap this year,' she replied in an equally sly tone, motioning to the gaudy lights and chandeliers that hung from the overarching ceiling, and the women in their enormous shining gowns, and the men in their sharp velvet suits. He nearly choked on his drink trying to stifle a laugh until she added, 'I was talking about you, sir.'
'What-!'
'Your tie is coming undone, and your hair is a mess.'
He feigned a hurt expression and placed a hand on his chest, where he found that his tie was in fact coming undone.
'Must have been that lovely drunken woman who tried to persuade me to run away with her,' he grumbled. 'Do you mind?'
'Not at all, sir.' She loosened his tie completely before she began to tie it back again. When she was finished, he ran a hand through his hair to flatten the disheveled mess and looked at her expectantly.
'Well, how do I look?' he asked.
Riza arched an eyebrow as she looked him over. His solid black suit fit him well. It enhanced his height and his slim waist and the red tie brought some color to the tuxedo. His smooth face held only the slightest trace of a flush from the heat and his long trek across the ballroom, and his dark eyes were bright with a boyish excitement that made him look a dozen years younger. His shoulders were relaxed, and though he had an air of arrogance about him he looked entirely at ease despite the large and noisy crowd, a fact that she found reassuring, given that he had been struggling with anxiety ever since the 'Promised Day'. It was a sure sign that he was finally recovering, and she was glad to see him looking so calm.
One of his hands rested in his pocket, and the other held the small glass of cheap champagne, and she could still make out the faintest of scars on the back of his hand. She could smell his cheap cologne even from here, and his hair was slowly returning to its disheveled state, and his tie was somehow already coming unraveled again.
'You look like a rogue,' she told him matter-of-factly, though she had a different, more risqué opinion of him in mind that she kept to herself.
'Why, Riza, you are even more beautiful when you are insulting me. I shall never get over it. You have slain me with your fiery temper, and your bright eyes, and your-'
'Sir, I think we should stick to what we are best at,' she suggested, smiling wryly. 'And in your case, you should under no circumstances wax poetry to women.'
'All part of the show, Riza,' he assured her with a chuckle as he took another drink.
'The show,' she murmured thoughtfully. 'To hell with the show. I feel ridiculous,' she confessed, so quietly that Roy almost didn't hear her over the band, which now began a rousing tango.
As trumpets blared and bows glided across strings, he turned to look at her, standing there beside him so stiffly that though anyone else would say she had excellent posture, he knew that she was positively uncomfortable.
A silk gown hugged her slender figure, its radiating crimson color bringing out the light blonde curls that ringed her bare shoulders. Her hair had grown long in just the last year, but not long enough to hide the bold emblem of flame alchemy which was clearly exposed by the backless dress.
'Ridiculous?' he queried. She appeared to any outsider to be carrying herself with grace and poise- her shoulders stiff, her chin held high, her carriage absolutely impeccable. He was standing so close to her that the delicate scent of her perfume masked the overwhelming heat of the ballroom. She looked intoxicatingly beautiful, and standing so close to her, he felt like a drunken fool. 'Ridiculous?' he repeated, at a sudden loss for words. 'Far from it, I'd say.'
She held the tiny glass in her hands and swirled it thoughtfully before glancing over at him in playful accusation. 'I'm surprised you aren't tripping over your feet to flirt with me like you do with all of the other girls.'
'Believe me,' he assured her with a laugh, 'I'm trying. I stumbled the entire way over here. Nearly spilled your drink on a general, too.'
A sudden male voice spoke from behind Roy. 'I almost wish you had, and then we would have been rid of you sooner.'
'Fuery!' Roy greeted the younger man, clasping his arm in a handshake. 'How have you been?'
Fuery still had the face of a teenager, but now his shoulders were broader and he was several inches taller, and his cheekbones were becoming more prominent on his fair face. Riza felt a strange parental pride glowing in her chest at the fact that he had matured so well.
'Everything is great,' Fuery replied happily. He too held a small glass of alcohol, but it was yet untouched. 'The band sounds fantastic.'
As he spoke, the music reached its peak. The men on the ballroom floor dipped their partners simultaneously before turning with them once, twice- and then they flawlessly slipped back into their step routines. Slow, slow, quick-quick, slow. Slow, slow, quick-quick, slow. Pause, dip.
'Ever danced the tango, Mustang?' Fuery teased, noticing that their focus had shifted.
'I have, actually,' Roy replied smoothly. 'Not recently, though.'
'Why not give it a try?' The younger man smirked, glancing pointedly at Riza, who glanced pointedly at the couples turning in unison.
'Ha, ha,' Roy laughed dryly. 'An excellent proposal!' He turned to Riza, and though she fully expected him to have the apologetic look of a man who was only doing something to appease his friend, the eyes that met hers were genuine. He took her hand and she looked up at him breathlessly. His entire body radiated heat and as he looked at her with those dark, burning eyes she felt a blush creep unbidden into her cheeks.
'Well, Riza?' he said quietly. 'May I?'
'Of course, sir,' she replied politely, but though she kept her emotions in check he did not miss the clear red flush on her face that matched her dress.
'Excuse us,' Riza told Fuery, handing him her glass. Roy did the same before he took her hand and led her to the middle of the ballroom floor, a large square of brown wooden paneling where at least four dozen couples continued to twirl around each other.
They reached the floor just as the golden trumpets paused for breath before they blared a new melody, this one dark and sensual. Roy turned to face Riza. One of his hands wrapped around her waist and pressed against her back, and his hand was warm against her bare skin; the other clasped her right hand, where she could feel the callouses and ridges of scar tissue there. She pulled her other hand up to rest delicately on the middle of his back, realizing not for the first time how well he carried himself in a suit.
She glanced up at him without a trace of nervousness and he looked down at her with a smile before squeezing her hand gently.
The trumpets blared the rising chorus and the strings sizzled with heat, and they stepped off together.
Slow, slow, quick-quick, slow. Riza kept her head high and her back straight even as Roy swung with her in a rapid turn. Their footwork was less than perfect, but not once did they falter. Riza was as confident in heels as she was in a military uniform, and she stepped easily with him as they traveled across the ballroom floor.
'You can relax a little,' Roy chuckled, looking down at her stiff shoulders. 'It's not a waltz. You need not be so stiff.'
He stepped into a deep lunge and she released her head back as he dropped her to a dip, a motion which brought them so close to each other that she could feel his warm breath against her chest. They hung suspended for two heartbeats before he brought her up in a flourish and they twirled once more.
Riza had to admit that he was an excellent leading partner. His steps were certain, and his posture impeccable- fitting, given his miltary background. Though she wasn't quite sure where exactly he had learned to tango, he clearly had experience. The hand he kept pressed against the small of her back drew her close to him and allowed her to feel his every movement and predict his next steps so that she was able to easily keep pace with him.
She let herself relax a little.
'Where did you learn to tango, sir?' she asked breathlessly. As he used the hand on her back to pull her closer to him, she melted into his touch and followed as he turned.
'My foster mother taught me,' he replied, equally breathless. She noticed that his hair had become a wild mess once more. 'And you?'
'Self-taught,' she said. He looked at her with arched brow and she smiled at him.
'Mm. Not too shabby for self-taught,' he complimented. 'You move well.'
He lunged again, and this time they fell together, their bodies pressed tightly against each other as they dipped to the floor. She relaxed into his steady grip on her back, captivated by the intoxicating smell of his cologne and the way his lips parted just slightly as they skimmed over her collarbone and tickled her neck.
Then the song swept them off at a brisk pace across the ballroom floor. Slow, slow, quick-quick, slow. Slow, slow, quick-quick, slow. They moved as flawlessly as a flame cavorted around tinder, as easily as breathing. She dragged her knee against his thigh as they stepped across the wide ballroom floor and let her ankle wrap around his to force him into another turn. It was worth it to watch the surprised look in his eyes as she momentarily took control, smirking at him as she did so.
'Fair enough,' he said, and grinned slyly at her before lunging and dropping her so low to the floor that for a moment she was rendered breathless at the sudden speed, and then he chuckled to himself at the look of utter shock on her face.
'I had to return the favor,' he laughed as he snapped her back upright and stepped with her across the floor once more.
'You bastard,' she growled, though she looked up at him with laughing eyes.
The song increased in tempo and Roy compensated by increasing the pace of their steps. Their footwork had become nearly faultless as they adapted to each other's styles. As she once again curled her ankle about his and let her knee slide up his thigh before they turned, her crimson dress swirled around their legs, an inferno. Her eyes met his wordlessly, and as they continued stepping they did not break eye contact.
In his eyes she saw fire, and she met his burning gaze with her brown eyes like glowing embers. They were stepping at a dizzying pace now, and he slipped smoothly into another deep lunge, this time catching her by surprise when he dropped her to the floor so that she nearly lost her balance, so focused had she been on his eyes instead of their steps. She recovered well, though, gripping his back tightly and clinging to his chest and letting her leg wrap around his as she let her head fall back before they fell back into step.
She could not help but be enchanted by him. It was exhilarating to be so close to him, to his body that radiated warmth and strength, and they were so close now that the only thing separating them was just a few layers of clothing. She yielded to his touch, allowed herself to relax into his embrace, let herself move with him and glide with him, her passion all the while burning beneath the surface of her skin like molten lava beneath the surface of the earth.
He noticed her slight shift of posture as she relaxed and compensated by spreading the hand on her back so that it gave her greater support as they turned again, legs and feet intertwining effortlessly as they did so.
The trumpets reached a crescendo and Roy's heartbeat roared in his ears, his pulse beating in time with the music. When he lunged and dipped her to the floor, his warm breath tickled her neck and Riza could smell sweet liquor. She longed to taste it on his soft lips.
He whispered her name against her collarbone, and as he slowly drew her back upright, she opened her eyes, and even as they stepped off once more she found that she could not keep her gaze off of his lips.
The song was coming to its end. They spun one last time, and just when the ensemble played their final note he dropped her to a low lunge and they hung there, panting, with her releasing her head back so that her curls brushed the floor and him gently resting his cheek against her chest so that he could feel her rapid heartbeat pulsing against his ear. The surrounding crowd applauded the couples on the ballroom floor, and when Roy finally opened his eyes he watched the man beside him sloppily kiss the woman that he held close. Roy felt a strange passion consume him. If he was going to do it, he needed to do it now, quickly, before the spell that held them together was broken and they lost their chance.
He lifted Riza ever so slightly and she opened her eyes, met his gaze, and then he watched as those brown eyes flickered to stare at his lips.
She met his burning eyes once more, asking permission, and, moving as if in slow motion, as though his body was made of the same molten lava that flowed in her veins, he leaned forwards, closer to her face, to those golden-brown eyes, to that pale, red mouth and he pressed a gentle kiss to her lips and welcomed the flame that roared in his heart, fueled by her touch. She released his hand and let her arms slide up to wrap around his neck and he gently lifted her to standing, and though she still kept her arms about his neck and he still held tight to her slender waist, they ended the kiss and for a moment only stared at each other in breathless exhilaration.
'Beautiful,' Roy breathed, gazing down at her flushed face and bright eyes.
'We agreed not to wax poetic in public,' Riza murmured, pulling his face closer to hers. He chuckled, and she was so close to him that she felt the laugh rumble in his chest.
'I guess I'll have to make it up to you somehow,' he said.
The strings began a new chorus and the couples on the ballroom floor began turning about them once more, but neither Roy nor Riza made any motion to leave the floor.
'It's hard to think with you staring at me like that, Riza...' Roy managed. Breathing had suddenly become a challenge, so intense was the inferno that rooted them both to the spot.
They stood there in the center of the ballroom floor, captivated by each other's eyes, motionless while every other couple on the floor twirled around them in complete oblivion to the flame that burned in the center of the floor.
Shining silver gowns swept past them at dizzying speeds and tall men in black suits led their partners with daring, drunken confidence. Slow, quick-quick, slow, slow. The lords and ladies turned so rapidly that they blurred together in the corners of Riza's vision and she imagined that they appeared as great clouds of smoke, so thick had the air become. Her chest felt tight and she had the sudden irrational desire to give in to the thoughts of fire that so consumed her, and as she stared unwavering into Roy's dark eyes she knew he felt the same.
There were a dozen things that Roy wanted to tell her, a hundred words that sprang to his lips, the lips that still scorched from where she had kissed him, but as they stared greedily into each other's eyes he found that words had suddenly become meaningless. The world around them had disappeared, and the fire had consumed them wholly. And strangely, they found that it was enough to stand and burn together.