Sirius: Sirius. Sirius Black.
James: Are you?
Sirius: Am I what?
James: Sirius
Sirius: Yes, I'm serious
James: You're seriously Sirius?
Sirius: I'm serious, I'm Sirius
James: Seriously? Well, Sirius, I'm James Potter
Sirius: I, Sirius, am seriously pleased to meet you in all seriousness
James: Oh, Sirius, I'm seri-
Lily, crying in the corner over Petunia: CAN YOU NOT