Originally Posted by autistichalsin
So Astarion is comfortable saying he won't share the player with Shadowheart, Lae'zel, Wyll, Karlach, Minthara, or Gale, is comfortable saying he isn't ready at the Drow brothel if this is done before the Cazador confrontation, is willing to break up with the player if they have sex with Mizora without talking to him first... but when it's Halsin, magically, he becomes a horribly weak and pathetic people pleaser who could NEVER EVER say no to changes in their romantic relationship? That's somehow more probable than the idea that he is okay with Halsin because he has experience with poly relationships (which he explicitly GIVES as his reason) and which is in contrast to Shadowheart and others, who he says would inevitably end badly because they've never done this before?

The new Mizora reaction is still not implemented and it's only for Spawn Astarion. I don't know whether it's pre- or post- his personal quest. The current one for Ascended Astarion actually fits pre-Cazador spawn where he pretends he's fine with it. His body movement is more like him and especially the laughter is the theatrical, high-pitched Spawn exclusive giggle rather than the deep laugh of the Ascendant. Seeing that AA is the most possessive romantic partner, I'd imagine him to be upset about Tav going behind his back and someone else getting a piece of his "treasure" while he wasn't looking. In one banter with him Minthara comments what a special bond he has with Tav that both his eyes and fangs don't wander to other necks. In the epilogue party he even says "Heavens help the fool who tries to get in our way". He and Tav are joined at the hip and he's always observing them.

Even if AA or post-Cazador Spawn agrees to sleep with the drow twins he still gets PTSD.

He doesn't like Halsin and merely tolerates Tav's affair with him. Just because he agrees to the arrangement due to the druid's experience doesn't mean he's happy about it. I'd say the main difference pre-Cazador is that he greenlights it because he's scared of losing Tav (and it's something he doesn't have to participate in like in Sharess' Caress). After his quest he becomes more confident that Tav won't leave him (especially AA), but it's still something he allows, not wants.