The three options you have at first are "lash out with your elbow", yell "Stop!" or "grab a weapon". The thing is, Astarion is immediately off of Tav and already backing away (and he looks scared) so he's not seeming quite so dangerous anymore (to me). Then he says "I wasn't going to hurt you! I just needed blood." Then Tav will automatically freak out and make a stake and wave it around at him, and he knocks it out of Tav's hand. Finding out my friend is undead (and was the whole time I knew them) would NOT make me want to murder them immediately, especially if they were not attacking me. I wish Tav would only grab that stake if you pick the very obvious "grab a weapon" option.
And now learning here that a stake in the heart only kills Forgotten Realms vampires under specific conditions makes it extra annoying that they make it so easy to murder him in a cutscene.
+1 on this. My character would DEFINITELY grab the stake, but I am 100% for the option not to.
