It's actually not strictly true that the Aerie romance ends if you sleep with her. Although it is clearly the better roleplaying choice to decline, sleeping with her doesn't terminate the romance (setting AerieRomanceActive to 3.) What CAN happen, though--and I genuinely believe this was an oversight by Bioware--is that if you sleep with her, AerieRomanceActive gets stuck at 1, never gets committed, and therefore doesn't continue in TOB.
As coded, if you sleep with Aerie and say "If that's what you want, there is nothing I can do," RomanceActive is set to 2. Oddly, it is not set to 2 if you profess your love or ask her for an explanation. I simply cannot believe that it was a deliberate decision for Aerie to only commit her feelings to a PC who responds to her proclamation of a cooling-off period with a relatively dispassionte response, snubbing someone who tells her he loves her.
So I've fixed that in the flirt packs, and as long as you satisfactorily complete the romance, don't send her away, etc, AerieRomanceActive will go to 2 at the end. (Although don't expect her to be very flirty throughout the rest of SOA, she meant what she said about needing time to think! Feel free to try, though.
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