Why Didn't Sirius Tell Dumbledore About the Switch? (WAS: Black Laughing?)

[erisedstraeh2002]

No: HPFGUIDX 44246

Frankie wrote:

> <snip> without Peter, no one will believe that Sirius wasn't 
> Voldemort's spy himself (as explained by Dumbledore in
> PoA). 

Now me:

I've also wondered why Sirius was laughing at that point, since while 
it makes sense when you think he's the bad guy, it doesn't make sense 
(to me, anyway) once you find out he's actually a good guy.

What I've also wondered is why Sirius didn't tell Dumbledore about 
the secret-keeper switch after Peter's betrayal of the Potters.  
Sirius didn't meet up with Peter until the next day, so there should 
have been time for Sirius to talk to Dumbledore about this.  This 
also ties in with my wonderings about why the Potters didn't use 
Dumbledore as their secret-keeper in the first place.  Makes me 
wonder if they didn't trust Dumbledore for some reason.

~Phyllis