if you've seen the comic con video for season 2 of true blood then you saw the clip of eric telling sookie to trust him, even if you haven't its pretty straight forward, he leans in and tells her.
well i don't wanna throw out anything too far fetched but i'm reading all together dead and i know that the show is based off the books but they're different but if you've read all together dead and you've gotten to the vampire summit when andre corners sookie and tells him to take his blood, then eric shows up *:]* and convinces andre it'd be better if sookie drank from him (eric), and he tells her to trust him, i know its far fetched and that seems so far off but i wanted to offer it up cause i thought it was plausible. and hey its not like they're following the books page by page so who knows? it could be something else but idk.