When the spawn/Karlach kiss was leaked, people were asking for it for AA, too. And no one was calling it anything drastic then. I do think there's a bit of a double standard in judgement. When spawn does it, it's fine, but when AA does it, it gets a really... unnecessarily harsh view, in my opinion.
Don’t know where you got that from, personally I don’t like the Astarion x Karlach kiss. I think it fits way more for AA, a little less for act 2 Astarion and not at all for UA. I’ve never seen anyone be ultra happy with the kiss with Karlach. It’s too harsh, though you could argue that it was just because Astarion had been waiting for so long to kiss her and is just overly excited, and Karlach is just happy to be touched again. Also I’ve been saying multiple times that I like AA kisses, as have been many others. Barely anyone wants AA kisses to change. Only a handful of people here (!) who all of a sudden want new kisses for him. Why? Patch 5 kisses don’t even count because none of the companions had proper kiss animations. Patch 6 introduced new one’s for Everyone, whether or not they should’ve advertised them as Valentine’s Day kisses or not is a different thing entirely. I don’t understand why larian should change AA entire kiss animation catalogue when we all have been playing the same AA route and had not one complaint about it until now. What changed? We got smiling faces now, we should be happy with that. Meanwhile UA still has so much less than AA.
