This moment

[allies426]

No: HPFGUIDX 175413

--- In HPforGrownups at yahoogroups.com, "Steve" <bboyminn at ...> wrote:
> 
> bboyminn: 
> 
> Very close, I think, Allie, but not quite. The central
> point is that seconds after Lily was killed, Voldemort
> became Vapormort. So there was no time for a heart-
> to-heart.
> 
> Still, I think you have come close, but picture it 
> this way. Snape approaches Voldemort before the fact,
> and asks him to spare Lily. Voldemort says he will
> if he can, but if not, there are plenty of more
> worthy pureblood girls for him. 
> 
> Voldemort makes assumptions about Snape's motivations.
> Since he doesn't understand Love, Voldemort assumes
> Snape simply 'desires' her. 
> 
> So, the heart-to-heart, as we are calling it, could
> have happened before Voldemort went to kill the
> Potters. 
> 
> As always, I assume there IS an explanation, we just
> don't know what it is.
> 
> Steve/bboyminn
>

Allie again:

The canon reads something like "after she had gone," which also 
means after Voldemort had gone.  I can see the exchange happening 
after Snape returns to Voldemort at the end of GoF.  Just as an 
aside at the end of their primary discussion ("Oh, by the way, you 
know why I had to do that right?")