You are dating him and his damaged goods brat is not being controlled, but indulged.

I would break it off? Because if he was father material he would correct the little beast.

But if you want to try, you can't avoid talking to him about her.

We aren't like you. Our boilerplate, all dads thing, is "oh honey they're just kids, leave them alone"....because we want to be left alone and we can be "cross wire" protective.

It might help if before you broach the subject, get a feel for why he lets the lil bich be like that. Hes either uncaring and heartless like his ex (or) he sees it, doesn't know wgat to do, but its his job to protect her. And it may be just that. Males can be emotionally awkward and you guys are the ones that say the things that might make sense to us wben we can't and also the ones where you laugh and say "thats not something you have to protect, she's waiting for you to notice and get her to stop" Really.

But...still, MY BABY COMES FIRST and if you have a good one, all the others in a pile are not worth him to everybody.

One of ours has a cruel lil carbon copy of mom's evil. They told me they went in the kids room and she was standing on the baby.
I know how humans are and kids especially. I told them what it was and to be vigilant and use common sense with her.
But I wish she'd rot or something myself.

In the end tho, nothing toxic should lower the face of your good boy. Best wishes and if he cops out and won't show being a dad, then you are still looking, before he fails or zeroes in on your kid.

Good for you btw