Based on Chapters 167 & 185


He says I love you with his fist, spells affection with each knuckle bruised that streaks across his skin. This, this is what Kurogane knows, and so Fai can give it.

They never speak about it. They don't have need to describe what is implicit. And if they did, then it wouldn't be enough. They only know, and that is [enough].

And so, between the brute fists of the day and stolen breaths in the night, there are no words between them.