HELP Can’t cope with my sons dad and the new woman he’s moved in

Thing is, your ex is a dick and has always been a dick. You know he's a dick. Trying to remain friends with a dick is a foolish proposition.
You need to detach from him and move on emotionally. He's been a dick with this woman but you need to let that go. He can have his girlfriend around his son if he wishes - that's his right. The 'mummy name' issue is infuriating and you need to correct DS on that but otherwise stop expecting him to be decent because he's not.

I don't think you can do anything about your ex having this woman in his life, and DS's life by default.

I doubt you would be happy if he wanted to vet any new partner that you began a relationship with. It does sound quick and unwise, but there's nothing you can do so just need to let that go.

CM should be consistent. Is his job impacted by the pandemic? What reason does he give for late and varying payments?

And ridiculous that he wants DS to call her mummy. Correct DS and your ex every time.

Give it a rest water. Fucking ridiculous mumsnet bourgeois bullshit at its best there.

Op I wouldnt let your child around there, simple as that.

Its a shit situation. Unfortunately you will have no control over what happens in his house. This will include what your ex is encouraging your son to call this woman.
What you can't and shouldn't do is make your son feel bad or guilty about it. This a problem between the adults.
If you had any proof your son was at risk you could curtail the overnights to a few hours but you would have to convince a family court of the issues.
Yes its hurtful, yes your ex is definitely behaving irresponsibly. But he isn't breaking any laws.
Im really not sticking up for him. My ex did something very similar.
My daughter was slightly older and very quickly saw this woman (and her father) for who and what she was.
A bampot sadly.....
As for maintenance, you have every right to apply for the correct amount. I am out of touch with the procedure now but I'm sure there's an online calculator.
Im wish you all the luck 💐💐💐

Her name is x im mummy on repeat along with you only have one mum and one dad on repeat nicely

Cmo for the two faced twat

If he tries to protest about either tell him one mum one dad he wouldn't like you introducing a partner as dad 😉 and the child maintenance is not optional

It’s one of those situations where you have to detach what you feel from what action you can take.

The bottom line is that you have neither control or influence over how your ex lives his life. Agreements about how people manage new relationships and introduce them to children don’t always survive the reality when it happens. It will be a fucked up case of what the adult heart wants. Children won’t get a vote and ex’s definitely don’t.

You are wasting emotion and any capital you had with him over this. He doesn’t need or want to listen to you. You will need to find another outlet for your emotion. Sorry but that’s the only answer.

I've had this. My ex H and I got on fine. Spent Christmas together etc. New girlfriend came along, played nicely for a while, but has turned out to be a total horror. She leaves my kids out deliberately, and even though they (ex H and her) live together with her kids, she says that my kids are nothing to do with her and go buy them ice cream and leave my kids out.

Ex H is totally changed since he got with her. We argue at everything (apparently her kids are perfect and mine are spoilt and awful). It's been horrible. Luckily ex H isn't as bad as yours but it really upsets me that it has come to this.

I always just try to remember "nothing, no amount of money or anything, is worth your children's mental health".

On the maintenance front, assuming he is employed, get yourself in to the cms and get that formalised. That way he can't hold that over you. Is contact set in stone as that will likely be the next thing he messes with!

Yanbu.
The mummy ... name is outrageous and I would explain to my child that she is daddy’s friend and her name is all he need call her.
Your ex should definitely never teach his son to keep secrets. He really is a pratt. I suspect the girlfriend is jealous.

Oh yes do contact cms asap for maintenance it's your son's money.

Correct ds every time he uses mummy name.. Ring Cms about ex.
Ignore the rest..

howtobe nope I don't think it's ok to infantilise women. Plus she may not be of age which needs reporting.

@WaterOffADucksCrack

Jesus Christ leave the OP alone - it’s a turn of phrase and well you know it.

I’d be upset OP. I’m not even sure what I’d do but I’d be upset

Firstly if she's a girl you need to report him for being a paedophile. But I'm assuming she's a woman and you're being mysoginistic. Secondly she hasn't changed him, that's all on him.

Practically maybe say to your son "I'm your mummy silly" or ignore completely as it will blow over.

What you need to do is be civil and set a good example for your son. He'll know what's what as he gets older.