Help!

My fiancé has two amazing children and I am deeply involved in their lives and in their schooling. We are getting married in the future, and our life together is wonderful and full of joy. We have the kids 50% of the time and we(the kids, my fiancé, and I) all love each other.

That being said... their mother (HCBM) is throwing a fit about me attending parent teacher conferences for the children. She is claiming it will not be good for the kids and divide loyalties for the kids. But if she showed any kind of support for

my involvement in the childrens lives, they wouldn’t have to feel divided or like they had to be loyal!!!???

And I kind of wanted to hear what everyone thought about the situation.

Update: She is now claiming that it’s not appropriate for me to be there and that I am not a parent to those kids... she’s treating me like I haven’t held them after nightmares, cared for them, cooked for them, cleaned their rooms, done their laundry, helped with homework, helped with trouble at school, loved them, played games and had fun times with them... I am not a parent in her eyes.

And at the same time she’s saying I’m not a parent, she is degrading every foster parent, every adoptive parent, every grandparent or other family member that takes in a child is not a parent either.

I am hurting so badly inside... I’m hurting for myself, my fiancé(who the HCBM is calling a bad dad for fighting to have me there)... but most of all I am hurting for those kids.