altrium anniversary

[misheard]

Title: altrium anniversary
Fandom: Fate/Grand Order
Character(s): Mysterious Heroine XX, Artoria Lily
Pairing(s): Artoria Lily/Mysterious Heroine XX
Genre: Fluff/Smut
Word Count: 625
Rating: NC-17
Warnings: Underage
Summary: Mysterious Heroine XX is awkward about sex. Apparently the same does not apply to Saber Lily.
Notes:

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Mysterious Heroine XX fondly remembers her days as a student under Professor Tesla. He taught her many things about the best ways to use Altrium as fuel and the superiority of alternating current.

She’s not completely sure why he was in charge of sex ed, though. There was one class, the entirety of which could be summarized as ‘sex is terrible and distracts from better things, wear a condom’.

It didn’t matter to her when she was focused on hunting down evil Sabers, and then she got a real job with the Galactic Police Force and all her free time went out the airlock. Even when she does have a moment to herself, she’s usually too tired to do more than grab a snack and curl up in front of Jetflix for an hour.

Tesla’s lesson hasn’t been relevant to her until now, with Saber Lily sitting on her lap and kissing her neck. Her half-jacket is already on the floor, leaving XX in her bikini.

“L-Lily…” She shudders, threading her hand in Lily’s hair behind the ribbon.

Lily smiles against her skin. Ever so sweetly, she asks, “Would you like to lie together, XX?”

XX’s face turns even brighter red. “I-I’ve never - I know I’m supposed to be the teacher here, but I don’t know the first thing about… that kind of thing.”

If anything, that makes Lily’s face light up even more. “That’s okay! I can be the one to guide you, this time.”

“…You can?” Lily is still a teenager, why would she know any more than XX does? Does she have more experience than her already??

Lily laughs, a touch self-consciously. “My first teacher was Merlin.”

Ah. That explains a lot.

When XX nods, Lily tugs her bikini top over her head. With the same diligence and enthusiasm she applies to her training, she cups one of XX’s breasts in her palm while sealing her mouth to the other, tongue teasing her nipple to hardness.

XX moans, before clapping her hand over her mouth. Wh-what an embarassing noise…!

“It’s okay to be loud,” Lily says between licks. “It lets me know that you feel good, and that makes me happy.”

Lily’s sincerity is hard to say no to. XX doesn’t muffle her next groan, just hoping that the walls in Chaldea are thick. Lily switches breasts, and XX’s cry of her name makes her smile.

XX aches between her thighs, more than she has for a long while. Nervousness keeps her from pulling off her bikini bottom herself, but her awkward shifting gets Lily’s attention, and she slips a finger underneath the fabric.

“Wow, you’re really wet,” she says, like she’s commenting on XX’s swordplay. She settles between XX’s legs and pulls her swimsuit the rest of the way off, before leaning in.

Nothing could have prepared XX for the wet heat of Lily’s tongue where she’s most sensitive. She shakes all over, toes curling, repeating Lily’s name like a mantra and desperately trying not to grab onto her hair.

Lily hums, the vibrations traveling up XX’s spine. She licks a long stripe up before wrapping her lips around XX’s clit, and that’s as much as XX can take before she’s thrown over the edge.

Once Lily’s attentions start to become painful with XX’s oversensitivity after climax, XX pushes lightly on Lily’s shoulder. Lily looks up, confused. “Did I do something wrong?”

“N-no, that felt amazing, I just… already came…” The last two words are a mumble, and XX tugs her hat down to try to hide her blush.

“Oh. Oh! I’m glad you liked it.” Lily smiles, so bright and genuine that XX has to push her back down onto the bed.

“Teach me how to do that to you.”