Cats in the Box

He makes the most delicious noise when her fingers close around his cock, squirming against her in this cramped closet.

"Quiet, Daodao." She whispers with a teasing smile. "Wouldn't want someone to find us, would you?"

"You try to be quiet when I'll shove two fingers up your-" Gudao squeaks again as she squeezes, and he wisely chooses to hide his face in Gudako's shoulder to muffle his voice.

"I don't know, Daodao." She strokes him slowly, feeling him up from head to base. "One of us is acting like a dog in heat, and that sure isn't me."

He grumbles something incomprehensible, pressing his face against her neck, but his cock doesn't lie, twitching in her hand. She knows his kinks well (she knows him better than anyone else.)

"Wonder what would happen if we could get caught." She muses out loud. "If they knew humanity's last masters were fucking in a closet."

"Oh, god." He bucks into her hand. "If Mash saw me like this, I would die."

"What if it was Artoria?" There is no need to specify which one; she means Caster, their Caster, the only one who came close to knowing the two of them.

Gudao inhales harshly. "... Think she'd join in?"

"I think she'd freeze in front of the door with that adorable look on her face." Gudako's free hand sneaks up his shirt, teasing his flank. "It would be so easy to just... pull her in."

"Squeeze her between the two of us."

"You could fuck her from behind while I suck on her clit."

"Or I could fuck her while she eats you out."

"We could positively obliterate this girl. Wouldn't it be a nice sight? Artoria... shivering all over... our hickeys on her inner thighs..."

Gudao must agree with her, because he lets out a loud moan, his hands suddenly grasping her hips. "Gudako... I- I wish..."

He never ends that sentence. Suddenly, the closet door opens, and light floods their little nest.

"Senpai?" Mash blinks. "What are you doing here?'

Gudako looks down.

She is alone. Again.

Only one master survived the fire of Chaldea. Such is the truth as the universe perceived it. As such, only one of them can truly exist at the time. When no one else is there to perceive them, they can both just be, little cats in that dark box, but the second they are observed the world shifts to accomodate.

Today, that master is Gudako. Another time it could be Gudao. Artoria, Artoria and her fairy eyes- she's the only one who has noticed the discrepencies in Chaldea's recorded history, the only one who picked up that the master of Chaldea uses different names or pronouns over time- but even she isn't aware that they are two different people switching place on this theater. No one but Gudao knows about Gudako. No one but Gudako knows about Gudao.

No one but Gudako can save Gudao.

"Nothing, Mash. I was just resting." She gives her kouhai her best smile. Mash loves them both (you don't need to be understood to be loved, and Gudao and Gudako both long gave up on being understood) which means she's the most prone to worries. "Did you need anything?"

(In Gudako's balled fist, lies the thinnest smear of precome, the only proof that her dear friend ever existed at all.)