Accidentally started a romance with Kibella, help!

[Aleisis]

I tried to be kind to Kibella and let her know there was more to life than death. Now she wants me to go to the crypt with her and I have the 'I want to talk about Us' option. I don't want to be in a relationship with her, or cause jealousy, but I'm afraid if I break it off now it will put her back into mindless murder-hobo setting.
I can't reload because I've played almost a whole chapter since the 'ritual' event.
Is there a way to get out of the relationship without seriously antagonising or hardening her?