"Hand to fucking Merlin they're like a plague," he says, nearly a hiss, and it's difficult to discern if that's an insult or... what. Surely it can't be fondness.

He heads out the back, obviously expecting Sebastian to follow him - he'll let him out, lock up, and they'll both be on their ways for the time being.

(Severus has a few things to rip out of his head before he faces anyone. It's just something that has to happen.)