I imagine your demeanor in being quiet and not showing emotion was unsettling to her, as she can see you are not falling apart and waiting for her return. I'm sure standing up for yourself in the case is also unnerving, particularly if you let her have her way often in the relationship. I have the opposite dynamic. I took care of everything, made all the decisions (because he never really participated and things had to get done), and was the strong one. I think seeing me be quiet, patient, and avoiding emotions in my communication is unsettling him.
