When Shisui remembers that Genma was close to the Yondaime, he—understandably—freaked the fuck out. The Yondaime's Shisui's hero; he invented a technique that let him travel places faster than anyone else, and if there's one thing Shisui loves other than Genma, his kids, and Anko, it's going fast. He's Shunshin no Shisui, goddamnit, and he's known for being one of the fastest people in Konoha, because of his use of the Shunshin. That's what got him his fucking name.
And there were stories - stories that the Hokage's guard could use the Hirashin, just like their master and teacher.
Or, in other words: Genma can use the Hirashin.
(If the hearts in his eyes are a little more pronounced after this realisation, well. That's no-one's business but his own.)
Anko notices, because of course she does. She's Anko. And because she notices, because she's Anko, the first thing she does is drop out of fucking nowhere and tease him about it.
"So," she says, one of her signature smirks tugging at her lips, "What's got you so moon-eyed over Shiranui?"
"I am not moon-eyed!" Shisui protests on principal, before pausing as he realises that yeah, he's moon-eyed, all because his boyfriend is one of only five people to use a technique to make them the fastest people in the goddamn world. Fuck, he's easy.
Or maybe that counts as hard-to-get, given that out of only five people in the world who fall into that category, only three are still alive. Shisui's not sure that counts though, given that he knows all three of them.
Anko laughs at his silence, full-blown, head-thrown-back cackles. "You're moon-eyed as fuck," she says, and Shisui can't bring himself to argue. "C'mon then." She drops to the ground, rests her chin in her hands, tilts her head, curious. "Spill. What new realisation have you had that's got you so newly attracted to him?"
"He can do the Hirashin," Shisui says, and it comes out breathier than he would have liked, but fuck, who can blame him? His boyfriend can do the Hirashin.
"Yeah?" Anko says slowly.
Shisui turns to his best friend and stares at her in disbelief. "He can do the Hirashin."
"Well, yeah," Anko says, "but he needs Raidou and Iwashi with him to do it."
Shisui throws his hands up in the air, and goes back to watching his cute little genin try their hardest to blow each other up. It's obvious she'll never understand; Anko doesn't have the same desire to feel the wind rushing through her hair, to watch the ground speed past below her. Shisui has that desire, and all he can think of is what it would feel like to be transported by the Hirashin. Shunshins are fast, the fastest mode of single-person travel out there that still has living users. But the Hirashin...
The Hirashin is faster, and Shisui can't stop thinking about it.
Anko, the fucking traitor, tells Aoba. Aoba, because he's an insatiable fucking gossip, tells Raidou. And Raidou, because he's a dick, starts flirting with him. It's joking, but it alerts Genma to something, because every goddamn pick-up line falling from Raidou's traitorous fucking lips have something to do with going fast. Or flying. Or thunder.
Basically, anything to do with the Hirashin.
Shisui's been side-eyed so many times he's about ready to murder Raidou, regardless of his importance in performing the Hirashin.
Of course, before he actually reaches that point, Genma corners him in their apartment.
"So," he says, and he's smirking around that fucking senbon, drawing everyone's attention to his goddamn mouth—god, Shisui never thought it possible to be jealous of a needle—"you're attracted to the fact that I can do the Hirashin."
"No," Shisui corrects, because if his boyfriend's going to fucking call him out, he's gonna call him out on the right thing, damnit. "I'm attracted to the fact that you're one of the fastest people in the world because you can do the Hirashin." Then he smirks right back at his boyfriend, and adds, "Or, at least, one-third of it." Genma blinks, steps back, just a bit and Shisui smiles, taking that split-second of confused distraction to shunshin out of the apartment.
"Shisui!" Echoes out of their apartment's open window, but Shisui doesn't look back; because the only people more adverse to talking about feelings to other people are Itachi and Kakashi, and Kakashi can't even talk about feelings with himself.
Honestly, Shisui thinks he's doing pretty good.
"Anko," he whines, knocking on her window, "Can I stay the night?"
Anko snorts, opens the window and lets him in. "Trouble in paradise?"
"No," he says shortly, "I'm just running away, because Genma knows that the Hirashin makes me more attracted to him."
Anko freezes, then doubles over in helpless laughter. Shisui would join her, but this laughter is at his own expense, so he just sits and stares balefully. "it's your fault, you know," he says, "you're the one who told Aoba."
"Sorry," Anko gasps, waving her hand around, "Sorry, sorry." Then she smirks, entirely unrepentant, and says, "It was just so funny!"
Shisui throws a pillow at her.
The next time Genma corners him, it's less being cornered and more being pinned. Shisui won't ever complain about that, but he will complain about Genma pausing his ministrations to say, "I didn't mean to make you uncomfortable." Shisui whines, irritated, but Genma ignores him to continue talking, the asshole. "I'm sorry I did so. But, you shouldn't have to feel uncomfortable about things like this, okay? I want you to know you can always tell me things like this."
Then he doesn't do anything, just fucking looks at Shisui like he's expecting him to say something. Shisui whines, leaning up for another kiss, but Genma avoids it, still watching him. "What do you want?" Shisui asks, desperately.
"I want you to know you can always tell me things like this," Genma repeats.
"Fuck, okay, I get it!" Shisui complains, "Just kiss me again, you dick."
He doesn't, at first, just smiles, soft and filled with adoration. "I love you," he says.
Shisui softens, relaxes into the couch and says, "I love you too."
And finally, finally, Genma kisses him again.