[Taven03]

You should be mad… But also keep in mind some of the following. (sorry if this sounds awkward I rewrote this and now it sounds weird)
It sounds like she might be having trust issues. I think things will be alright with time… Remember the ex card is a big thing with both men and women. She might have been slut shaming but the underlying cause is that you are his ex and you have right to be mad at her. If you can build up that trust again with her and find ways to reassure her that before anything happens between you and him, that you will inform her. Also try to make a girl’s night and leave the guys behind.