palabravampiress
Bidet of Evil
I always took it that she had met someone when she went to L.A. and done the deed with them. In saying that, her comment about it all being very normal, you don't have to actually have had sex to know whats 'normal' and whats not. And then the comment about being a good girl, contrary to what we are led to believe from the Buffy/Angel and the Willow/Oz relationships most teenegers experiment sexually before they actually go the whole nine yards, so more than likely Cordelia may have some experience with oral sex and what do you call it in America? third base? I don't see how Xander and Cordy could have went out that long and not experimented.
Good theory.
I agree that Xander and Cordy were more likely to have a typical teenage experience than Buffy (with her vamp boyfriend) and Willow (since Oz seemed all on board the waiting train).