I interpreted this scene as Eric wants to say something but bites his tongue. Then Sookie invites him in, he turns to look at her and for a long moment and I think it’s a struggle for him to leave, but decides to call it a night or a silent goodbye. It’s bad timing for one thing, Bill will be arriving soon and the situation has fucked with his head. The invite sets up Eric being able to get into Sookie’s house if required, their interaction felt unfinished, so I’m assuming their final goodbye? has to be concluded.
Sounds about right to me.