My Friend, You've Aged

K so based on this cursed thought but it just hit me that in an au where Kuro got his fang back the KuroxShiro ship has some interesting potential.
I need them as fun drinking buddies and Kuro goes on missions together with Shiro- eventually with Yukio in tow. And eventually Kuro starts noticing Shiro's not as fast or doesn't recover as quickly and he realizes he's losing his human~