He doesn't quite understand. At some level, he can't quite understand. The last eleven years haven't really prepared him to understand beyond the occasional soft chatter from his mother about things he wasn't entirely certain he'd really caught hold of.

"Hey."

He doesn't actually have a brother. Still, there's something like fraternal impulse shoving him roughly into sitting on the end of Sirius's bed.

"What's up with you?"

Not the most delicate tack, true, but it's what he had.