When did Snape's spying career begin?

[dicentra_spectabilis_alba]

No: HPFGUIDX 36161

--- In HPforGrownups at y..., "nyarth_meow" <rshuson80 at y...> wrote:
> 
> But this raises another question in my mind.  Vampire or no, why 
> didn't Snape tell anyone about Lupin?  I know Dumbledore made him 
> promise not to, but at that early age was a promise to Dumbledore 
> really worth that much to him?  You'd think he'd be itching to run 
> off and tell everyone that that nasty Gryffindor is a werewolf, and 
> he was right all along... and instead he spends his remaining two 
> years at Hogwarts biting his tongue.  Was he threatened with 
> expultion?  Was his trusting relationship with Dumbledore actually 
> established much earlier than we imagine?  

Whoa!  Hold the phones.  Somebody check GoF again.  (I've only got PoA
with me today.) Does it *say* that Snape was a DE who turned or does
it only say that he was a spy?  What if he never was a DE?  That would
be interesting.

--Dicentra, noting that it would mean the demise of George and his
sister Diana and many other interesting theories