Gender Studies: on a scale of 1-10, how weird would this be?

With 10 being the weirdest, I'd give it a 2. Trust is trust. Either I trust the woman I'm with or I don't. I don't see it as degrees of trust within a romantic relationship. It would actually show me a certain strength of character that she would maintain a civil business relationship with an ex. She has obviously let the hate/discontent/ill will drift away. I wouldn't be jealous of her interaction with him. I've seen the other side where the hate and contempt is boiling.