More fundamentally, this Astarion route has him seeing everything in terms of power and control, so of course he's going to want to have power over you. It's why he turns you into a spawn in the first place. His animations are definitely adding up with the story Larian wanted to tell with his romance.
I know you are answering on DarkangelBeckons, but I just want to say: I like him having power over my Tav. Not everyone is complaing about that. BUT, my Tav wants to enjoy it like he did before the patch. They DID enjoy Astarion in the romance scene, the same as Astarion enjoyed Tav, even if you kneel down. I guess you haven't played AA Route, because there are a lot of differences in the scenes and some things don't fit together now. If they want to show him as an abuser with no love left, THEN, they need to change the Romance scene into a Rape scene, and evyerthing would fit together ;-)
"I would, thank God, watch the universe perish without shedding a tear."
