associative property of family

[misheard]

Title: associative property of family
Fandom: Fate/Grand Order
Character(s): Moriarty, Babbage, Frankenstein
Pairing(s): Moriarty/Babbage
Genre: Fluff
Word Count: 560
Rating: G
Warnings: None
Summary: Moriarty and Babbage aren't necessarily close just because of Fran. (Except they are anyway.)
Notes:

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It is a well known fact that the transitive property does not apply to found family. That is to say, if Moriarty is Fran’s family, and Babbage is Fran’s family, Moriarty and Babbage are not necessarily family.

It would have been easy enough to cut association after the race. Yet there are few who can keep up with Moriarty’s intellect, and fewer still of those whose company Moriarty enjoys. Who could cast suspicion on two men of genius bouncing their ideas off each other?

Well, it’s easy to be suspicious of everything and anything Moriarty does, but in this case…

“Professor.” “My dear partner.” Appellations with little more meaning than their names or ‘hey you’. If Moriarty turns more quickly at the sound of ‘professor’ than he does at ‘Archer’, that can be attributed to his eagerness for a stimulating conversation, or to the chance of Fran joining them mid-talk.

(And after all, is the mark of a true mastermind not being able to fool anyone, even yourself?)

---

“You like Mr. Babbage,” Fran says.

Moriarty briefly pauses in putting up Fran’s hair buns. “Men of our intellect gravitate towards each other, my dear. That is what they call a conflux of genius!”

She shakes her head, disrupting his hairdressing attempts. “Papa likes Mr. Babbage.”

“Wishful thinking on your part, I’m afraid.” It hardly takes a genius of his caliber to understand what she’s getting at. An understandable attempt to cement her little family together, but not a notion that needs any further thought dedicated to it. So he doesn’t think about it.

She sticks her tongue out at him.

---

That Babbage now willingly allows him to work on his armor, while Babbage is not inside the armor, is a mark of… something. He would call it trust, if he were a different person who could be trusted. Babbage knows him too well to do something as foolish as that.

(He has not yet had reason to make Babbage regret this decision. But things can happen, even if he would hesitate to break the confidence Babbage has in him.)

Babbage outside his armor is a rare sight. Every time, Moriarty commits his image to memory, adds new expressions to the index. Today he adds ‘exasperated fondness’ to the list, directed at him of all people.

“Nothing will convince you that I do not need a steam-powered sound system inside my armor, will it?”

Moriarty tuts at him. “It’s not a matter of needing, my dear partner, but simply a matter of whether I can add this luxury item. If I can - and of course I can - then there is no reason not to!”

Babbage sighs, with the tiniest of smiles on his face. “I suppose there is nothing for me to do but to thank you for the gift, then. With so many luxury additions, I feel as if I should repay you somehow…?”

Dangerous words to say to someone like Moriarty. Moriarty is about to tell him so, tease him for letting his guard down, but he looks at Babbage’s soft eyes and small smile and says only, “No need.”

Somehow he feels as though he’s already been repaid, with something more intangible than money or power, and yet infinitely more precious.

(Fran finds Moriarty an hour later holding his face in his hands and says only, “Told you so.”)