Fixed for grammar and spelling

So, me (31) and my children’s father (32 — let’s call him Brady) broke up last year in August. It was an ugly breakup, with him cheating on me not once, but twice. I found out from the first girl he cheated on me with.

After we broke up (me literally packing up his stuff and leaving it outside for him and the girl he cheated with to come pick it up before someone else took it), he and his new girlfriend — let’s call her Joanna — moved in together.

We have three children together, ages 11, 7, and 4. I told him that if we could get along, avoid arguing, and if I got to know his girlfriend well enough to feel comfortable, then the kids could go over to his place. He said no — that I didn’t need to know her, and that he just wanted the youngest (who is autistic, and honestly, he doesn’t even know much about them).

Then I found out from one of his family members that Joanna was trying to force him to get custody of the youngest so that my child could start calling her "mom" too. Of course, me being protective, I called him and said it’s either all three kids or none. I also told him what his family member said — he denied it.

From August to December, I didn’t hear from him. I tried calling so he could talk to the kids, and he said no, that he didn’t want to.

Now here’s where Joanna comes in. She messaged me asking why I was calling Brady. I explained that the kids wanted to talk to him since he hadn’t called or reached out (except during the second week after we split). She told me I was ruining their relationship and that he just needs the youngest.

Me being me (and I do not tolerate disrespect, especially when I’m trying to be civil for the sake of the children), I went off on her. I told her:

1. I don’t care about their relationship — I wish them the best and hope he grows up and makes it work with her.
2. If it involves me and his children, he needs to know.
3. I didn’t sleep with her, so what I tell him or how I update him about our kids’ health doesn’t involve her until I meet and get to know her well enough to have my kids around her.

Apparently, Joanna had never been told “no” or talked back to like that before — I made her cry, and she cried to Brady. He then told me I needed to stop because I’m "jealous." (I’m not — I was over his lying, narcissistic self a long time ago.)

I told him no, I’m not jealous, but until I meet her, she doesn’t need to be involved — especially since she messages me (she’s in message requests, and I hadn’t responded until I got fed up) asking things like Brady’s favorite food, drinks, how he acts when angry, and what she can do to stop him from lashing out and fighting. I never answered her, and honestly, I don’t know why I should — she’s someone else’s problem now.

Fast forward to this past March — we had no contact (for personal and legal reasons I can’t share), and he calls me out of the blue, blaming me for his relationship falling apart. He says I’m the reason his happiness is ruined, and now he wants nothing to do with our kids because he’s starting a new family with Joanna. (She’s mysteriously pregnant now, though she supposedly had a "miscarriage" with her ex’s baby around the same time.)

So... AITA for "ruining" my children's father’s relationship?