I posted a while back about self and exH having divorced and now co-parenting. Though, I should really say parallel parenting as it was an abusive marriage (financially and emotionally, not physically) and he remained controlling through the divorce which took an agonising 4.5 years to conclude. We don’t agree on much about parenting, he gets his sister to look after the children most of the time, which is probably better as she, despite not being a parent herself, has a much better way with them and is considerate of their needs. Things got tricky back in August when exH introduced new GF. New GF has never been married, no kids, in her late 50’s. He has no emotional intellect and she appears to be volatile and equally as clueless about the kids emotional needs. After a few months of dating, with kids not knowing her at all, she pretty much moved in. The kids were unhappy, they were not consulted about the sleeping-in situation and the relationship with dad and new GF has got progressively worse. She has blamed the children. Says they are rude and immature. She says the adults make the rules/decisions and it is not for the kids to have a say. She is very forceful and the children have responded negatively: eldest (19) won’t have anything to do with her and now gets depressed, middle (16) gets very emotional and also depressed, has become sullen, youngest (14) dislikes the upset in the house but pays little attention as, at dads, he has a gaming computer which he is on most of the time. New GF talks about the home as if it belongs to her, never refers to it as the childrens ‘home’. She changed the plans at xmas and NY meaning my exH dumped his kids for her on xmas day and I had to collect them for his as she threatened to dump him if he didn’t spend the day/night with her. She says Xmas and NY is different now, and wont ever be done like it was before - we had the same routine every year, where we split xmas day 50/50, which worked well for us all, but it didn’t suit her. She has now said he won’t be having them 50/50 over the summer holidays. I accept that it must be difficult for them as a new couple to navigate 3 teens, particularly as she has no experience of parenting, and he is hopeless. I think tbh she is worse than hopeless. At least he is passive, where as she is very aggressive. He won’t discuss my concerns about the children’s wellbeing. She doesn’t seem to want to understand their needs. It’s turning into a total sh** show with exH shirking his parenting responsibilities frequently in order to meet her demands and her getting more and more demanding of his time and creating arguments with the children over nothing. If they smile it’s wrong, if they don’t smile it’s wrong. They have to speak to her ‘properly’ and sit at the table with them for food etc. usually after she has been particularly aggressive. I have told the children they don’t need to go there, they can stay with me 100%. They are still choosing to go, because they want to see dad, which I am supporting for now. I am though very concerned about their mental health. Should I get professional advice? Should I advise them not to go? Should I butt out altogether and let them figure it out? Advice appreciated, particularly from folk in similar situation now or in past.