At first, they don't talk about it. Maybe because there's nothing to talk about, or because they don't know if they want there to be.
It starts with the screaming of Ayano's name at two in the morning, then Kido is straddling Kano and shaking his shoulders and begging him to wake up. He finally does when a tear falls onto his face, joining his own. When his eyes finally jerk open, they both freeze. Nothing is said. Not about Kido, quietly sobbing as the image of Ayano and desperation to save Kano from his sleeping and waking nightmares fogs her mind. Not as Kano lies perfectly still, without a single guard to protect him from his family. He tells himself later that he reaches up and hugs Kido for her, or maybe because he doesn't want her to see his honest face, but he doesn't believe it.
Her knees buckle and she lies gently on top of him, face in his shoulder and hands gripping his sleeves as he buries his nose in her hair and clutches her so close he's surprised she can still breathe.
"I'm here to protect you now," Kido murmurs. That's all. "I'm here to protect you now." When they wake up, Kido is still protecting him with her arms around him, though her face has long since dried and fallen into a sleepy calm. Kano wakes up before she does for the first time in years. Taking care of everyone must be tiring. He carries her back to her bed. The morning will be easier that way.
The next time is different. The next time, Kano wakes up at quarter to three and notices her light on his return from the bathroom. She's staring blankly at her wall, appearing and disappearing in slow, even repetitions. She doesn't cry, doesn't say a word. Her face is solid and cold. Blocking, concealing. Hiding. Kano is a gentleman, so he raps lightly on her door even though it's open a crack, and pretends that he didn't know what she was doing, and asks if he can sleep with her. No explanation, he just does. And he holds her as she shakes ever so slightly in her Kido way.
They're both strong in the day. That could be the reason, too, that their affairs go unspoken, so as not to acknowledge their own vulnerabilities as Kano smirks and laughs and Kido hits him or smiles at her new family. They're strong, they have to be, even after years of their strength wearing away moment by moment by moment by moment and now the visits are becoming more frequent and Kido's arms are home and Kano's breathing is the wind that blows away the storm clouds.
Even though they're alone when Kano says the first words about it, some little joke about Kido's bed being cold, the look on her face tells him loudly that he's gone too far, and he whispers his apologies into her hair two nights later during a thunderstorm that screams at them.
They start with forehead and cheek kisses. When they've just settled in or are just getting up, they'll press their lips softly to the other the way they have the rest of their body. In truth, it's mostly Kano who does this for a very long time. The first time he notices Kido kiss his forehead, he knows that she thinks he's asleep.
1:17 am, the morning after Ayano's birthday, they celebrate having not broken down and started sobbing. Kano lifts Kido into his arms so her legs are off to one of his sides and her head rests on his shoulder. He sways very softly in the moonlight as she runs tired fingers through his unruly hair, and together they hum the lullabies of their childhood. Kido cuts off the last note to take Kano's face in her hands. She stares at him for a minute, waiting for him to stop her, before kissing him once on the lip. He holds her more tightly and tries not to ask himself what's going on.
They have no idea what they would tell Seto, so they remain like that, with only the night keeping their secret.
Kano whispers "Stay with me."
Kido whispers "I promise."
And just like that, where Kido doesn't have to disappear and Kano doesn't have to lie, they find home.