Originally Posted by Zenith
Astarion still encourages you to backstab your ally and take control of the nethercrown for yourself.

I don't know if this was a bug or what, but in my game I did the back stabbing only to have Astarion promptly yell WHAT ARE YOU DOING!?! ARE YOU MAD!?! While I was stabbing. I'm like really dude? You just told me to.