Aziraphale could always tell immediately when the change had occurred, often even before Crowley did.
"Good morning, princess," Aziraphale crooned near Crowley's ear as the demon gradually stirred within the warm cocoon of blankets on the bed they shared. "Or should I say, afternoon," the angel added drily.
Princess? Why is he calling me—oh. "I'm a woman today," Crowley stated drowsily, stretching luxuriously. "That's nice." She rolled over in bed, burrowing her head under the pillow to block out the sunlight filtering through the curtains her lover had flung open.
Like a snake shedding one skin and growing a new one just as comfortable, the demon could slip from one gender into another with fluid ease. Crowley felt like a man—was a man—more often than not, but every now and then she'd wake up feeling distinctly female, or else like no gender at all, or even a sort of fusion of genders.* The longest consecutive span of not-male she'd ever undergone had been in the late Victorian Era, when she awoke from a century-long snooze to find herself a woman, and had kept the gender for five solid years. And then, just as sudden, he woke up one morning to find he was a man again. A pity, too; he'd finally grown accustomed to wearing corsets.**
Her thoughts rambling in the manner of a half-awoken brain, Crowley wondered vaguely how long she'd stay a woman this time.
Aziraphale seized the pillow currently shielding Crowley from the sunlight, causing her to hiss in annoyance.
"Come on now, rise and shine!" Aziraphale insisted. "The day's already half gone and you're the one who was begging me to take a trip to town today, weren't you?"
Aziraphale had really mellowed out after the Apocalypse that wasn't. After all, the Aziraphale of old would never have called Crowley "princess," or have used such a jovial tone to get Crowley out of bed, or prepared tea and toast for the demon's breakfast in a home they shared. This wasn't to say that Aziraphale was nothing but sunshine these days—he still had a stuffiness about him, not to mention the "holier-than-thou" attitude he still adopted fairly frequently—but he was certainly less of a snob than in the past.
Crowley supposed near-destruction of all one knew and loved could serve to mellow out a person, even if that person were an ethereal being who was supposed to prefer Heaven to Earth and do everything in their power to advance the ineffable plan. Crowley liked to think that at least part of the reason Aziraphale had grown so much more…affectionate? easygoing? empathetic? since their face-off with Metatron and Beelzebub involved the angel's realization that there was a certain demon he wasn't prepared to live without.
Whether that were true or not, Aziraphale had permitted Crowley to coax him into the countryside on nothing more than promises of "more than enough room to store all your books, plenty of tea and good country food and peace, and much more of this" – here, Crowley had pecked Aziraphale on the lips– "where that came from."
That impulsive kiss had startled both of them greatly, and they'd been a little awkward about it for a while—shyly stealing more kisses and tentative touches over the days it took to settle into their cottage in the South Downs—but by this point, several years later, physical affection came as naturally to the couple as lifting one's face to warm sunlight, or digging one's feet into soil just to savor the feeling of earth between one's toes.
Crowley wasn't positive these physical displays were even what humans would call "romantic." Rather, they were the touches of two beings who had almost lost their physicality, and each other, forever, and had learned at last to cherish what they had only barely managed to save.
Right now, for instance, as Crowley stood before the floor-length mirror in nothing but her boxers (all she slept in most nights), Aziraphale was standing behind her, lightly caressing the small of her back.
Crowley wrinkled her nose at the face looking back at her from the glass—today, this body just didn't look quite her.
"I'll just make a few tweaks," she murmured, and proceeded to will her shoulders into a more narrow shape, her hips wider, her hands smaller. She left her chest as it was—in any gender, she had never been quite comfortable with breasts, and so only grew them when it suited her tempting purposes. She moved on to her head: a mere thought caused her dark hair to grow longer, while another removed the slight stubble from her jawline and softened her facial features.
"How do I look?" Crowley asked Aziraphale, turning around and offering one of her classic devilish smiles.
"Very nice, dear," the angel answered abstractedly; he had retired to the bed while she modified her appearance, and sat there reading a book.
"Now, I just need to get dressed and then we can go." Crowley stepped into their walk-in closet. On one side, neatly pressed suits and shirts, trousers and ties, hung in orderly lines, while the other side of the closet housed Aziraphale's sweater vests, tweed jackets, and other assorted fashion disasters in messy piles.
Unfortunately, Crowley hadn't been a woman in several decades, and thus didn't own much in the way of feminine apparel anymore. After a moment's deliberation, she selected one suit and brought it out of the closet to hold up in the mirror. She eyed it with distaste—it was the most feminine looking outfit she currently owned, but it still screamed "male" from a human perspective.***
"I could do with a new outfit anyway," she decided. Furrowing her brow, she willed new garments into existence directly from raw firmament: a crisp black pencil skirt and matching jacket, with a crimson blouse beneath, and black snakeskin heels to finish off the look. Also, safely concealed beneath her clothes, her boxers had been replaced with something decidedly more risqué.
"Guess what kind of underwear I've got on under this skirt, angel?" she suggested to her companion on the bed, a wicked smirk dancing along her now crimson-painted lips.
"Oh, stop that," Aziraphale scolded. He did look Crowley over, however. "What did you have to go dressing up for, now I look…frumpy, by comparison."
"You could try a compliment, you know," Crowley remarked, but there was a smile hidden in her tone. Some things never did change when it came to Aziraphale. "And you always look frumpy in comparison to me, there's no helping that."
"Well, either way, I'm changing," Aziraphale harrumphed, and vanished into the closet.
Crowley looked herself over in the mirror as she waited for him to reemerge, twirling tresses of her long, silky hair around her fingers and checking that the eyeliner she had willed on tapered into a sharp enough point to suit her.
"There," Aziraphale said, stepping out of the closet, "now I'm ready."
The angel was now arrayed in an ankle length skirt—not tartan, surprisingly, but a plain pale blue that complimented his dark skin nicely—along with a loose-fitting white blouse and simple brown sandals. And, best of all, a bow (which was tartan; Crowley supposed it wouldn't be an Aziraphalean outfit if tartan were left out completely) was perched among the angel's dark curls.
Crowley had to fight a laugh—not at the fact that Aziraphale was wearing a skirt, which he did fairly often****, but at the idea that Aziraphale thought he looked any more fashionable in his new attire than he had in the old. That kind of skirt wouldn't have been out of place in the sixties (at last the angel's fashion sense was arriving at the sixties), but could hardly be called chic in the 21st century.
She was polite though: "You look lovely, angel." And she meant it, really. She felt a sudden surge of affection for the figure standing in the closet's doorway. This was her angel, her counterpart for millennia, her…cottagemate. And something more than that too. After all, an enemy for six thousand years could become a friend, and a friend who survived Armageddon with you, well…that was a dear friend, indeed.
"I couldn't let you be the only one to enjoy a skirt," Aziraphale said.
Crowley drew close to him to readjust his bow, which was in danger of tumbling from its roost on his curls, and kissed him on the cheek. Then she went to kiss him on the lips; he kissed her back, but when she tried to deepen the kiss he pulled away. He now had crimson lipstick on his cheek and mouth from where she'd kissed him, but she wasn't about to tell him that.
"No time for that now, Crowley, we really must be off—I want to be back before Antiques Roadshow comes on tonight."
That was another recent change in Aziraphale: Crowley had gotten him into television. And, to Crowley's dismay, it turned out that the angel had the worst possible taste in television programmes.
"Fine, fine. But," Crowley added hopefully, "there's always tonight..."
"We'll see, dear."
That was promise enough for Crowley. "All right, to the Bentley!"
Side by side, they stepped from their cottage and approached the faithful old car that had survived so much—including, in its finest hour, burning to a crisp as Crowley drove it ablaze to meet the end of the world. No one would know that, though, from the pristinely polished exterior of the car, thanks to the assistance of a friendly Antichrist.
Crowley opened the passenger door for Aziraphale ("though if we were going to follow human etiquette, you should really be opening mine for me." "Really? Aren't you always trying to tell me it was my side that invented Patriarchy?") and then walked around to the driver's side. She climbed in—a little more trouble in a pencil skirt than in trousers, but looking good is worth minor inconveniences—and started up the car.
"Buckle up, Az," she said, slender fingers caressing the steering wheel, "you know how fast I go on these country roads."
"Oh, dear," Aziraphale groaned as Crowley's high-heeled foot pressed the gas pedal. And away they sped.
Footnotes:
*She had started out with no gender at all, of course—there was no such thing as gender in Heaven, when she'd lived there way back when, nor in Hell. And for a long while, there had been no such thing on Earth, either. But when humans started formulating concepts of gender, Crowley easily picked "man" as most like what he was—except for every now and then, when the term just didn't fit.
**Not to say Crowley didn't sometimes wear the clothes of what human society called the "opposite gender"; he was a man for the whole of the twenties, for instance, but when on a trip to America he occasionally dressed as a flapper anyhow, simply because he liked the fashion.
***Why on earth did humans insist on gendering their clothes of all things? It had taken Crowley years to master the distinctions between "men's" attire and "women's" (it was especially difficult back in the days of togas). Sometimes she didn't bother obeying the "rules," but for the most part she did dress according to what humans would assume a person of her (or his, most often) gender would wear, as she found being misgendered annoying, like someone repeatedly mispronouncing your name.
****There had been a time in history, after all, when trousers hadn't even been invented yet, and Aziraphale was nothing if not old-fashioned. Besides, the angel paid even less attention to gender than Crowley did: he understood that most humans saw him as male, but really couldn't care less about what gender or pronouns any person threw at him, so long as they didn't bother him while he was trying to read.