Shiro realizes Keith has a crush on him a few months after he starts at the Garrison. It's honestly really flattering and he thinks Keith is a sweet kid and absolutely considers them friends, but he has Adam and Keith is a teenager and it's just baby's first crush Except Keith keeps growing up, getting taller, more in control of himself, really growing into a man and of course they're still friends but he doesn't have Adam anymore so Shiro's starting to wonder, especially since Keith's crush doesn't show any signs of letting up.