I'd guess it's supposed/expected as the effect of the guy saving her (or at least trying) on couple of occasions now, coupled with some time spent on their own when escaping the bandits, etc. He even gets the PTSD backstory to make Brigitte feel extra bad for him.It's curious, I don't remember when Brigette showed any interest in Simon either. I've just tried to be nice to him. Well, I hope that when the moment of truth comes, they give me the option to reject him, otherwise, what a bummer.