The invite is additionally surprising, to say the least. He's not even sure a text invite will work, but he tests the barrier and it gives way, allowing him entrance into Quinn's apartment. Stefan stands just inside the doorway, wanting to say so many things, but unable to not only articulate them, but express them to her in a language she'd understand. He's sorry he lied, he's sorry he's dragged her into this; there are things about some people she needs to know (some of which he'll leave out, others detail on the spot - Katherine, Damon; those two are unavoidable, the rest can be left out, for now), and warnings he needs to issue. None of that can be said at the moment, so Stefan just continues to look apologetic as ever.