so, always been a big fan of BG, and just recently got it on GoG to give it another run through. I'm in the middle of romancing Aerie, and twice now, I've heard Aeries romance music start but no dialogue. The second time, we were even in the middle of a move order and she stopped where she was while everyone else kept going. It seems like she's trying to initiate dialogue with my PC but can't for some reason.

Anybody ever seen this before? Any tips? I'm running Unfinished Business and Ascension, if that's any help.

These are generally known as 'stutter' bugs and can happen. They are generally caused by problems with the character scripting.

There can be a number of causes - for example, Quayle gives a quest to see Raelis - Aerie may then start stuttering until you actually talk to Raelis.

Alternatively, there are romance fixes in both the BG2 fix pack and the BG2 tweak pack - I don't know if they work with existing save games

so this stutter bug would also apply to non-romance convos, like party banter? because I was spamming ctrl+I to force banters and I noticed that Aerie wasn't initiating banter with anyone.

and would missing a romance dialogue due to this cause the romance to break?

well, the problem seems to have fixed itself. after the two failed to initiate romance convos mentioned in the original post, the next one happened as if I had done the previous 2 correctly, and now things are proceeding as normal. Infinity engine, you so crazy!