"I know I cant dictate who my ex sees but surely I have a right to know who will be staying with them?!" Sorry, but on this one, I don't think you do.
I know that in a civil, grown up world like yours you would tell your ex before you introduced your children to a new partner, but you don't actually have to do this, so long as the cildren are safe in your care. So in this case, so long as your ex is looking after his children and isn't putting them at explicit risk, you get no say over who he introduces them to.
Yes its def a case of he went about things the wrong way. Thing is there's a lot of background, he loves his kids but I have had letters from school about homework not being done, they dont have their school bags when they have stayed st his. I get them back filthy a lot, which hasnt got better since he has a gf on scene. Is she not bathing hers?! I worry about the attention my kids are getting now as they seem to be stuck on sn xbox or sent upstairs together to play when she is there. Thats supposed to be quality time with their dad. And he has had all 6 kids sleeping in one room when he got a 3 bedroom flat for HIS kids to stay at.
I cant make an informed decision about whether they are at risk or not as im not allowed to know anything about her. Also he is a compulsive liar and has a victim complex so who knows whst stories shes been told about me.
I find it difficult to let him get on with it knowing it could be detrimental to the kids. They haven't known stability with him since he left...
I guess what you are saying is that I dont have any legal rights unless I am concerned about their safety.