New GF/kids parties

[namechange003]

Trying to see if I am being unreasonable here..
ExH new girlfriend (of a couple months; 20 years his junior, only 10 years my junior). I've posted about her before but have since met her, seemed perfectly nice in the 2 mins I saw her! She is already basically living with him and there's yet to be a time she isn't there when he's with dc's in the last month or so.

This weekend he invited her to go with him to a party of dc's friend, still young so parents always there. He also left other dc alone with her for a period of time. Aibu to have found this quite upsetting? A lot of my friends are the other parents and I found out about it by one of them asking me whether exh had bought his niece/daughter from previous relationship!

I left exh and he was an awful manipulative and emotional abusive partner, it was a huge relief to find the courage to leave and quite honestly didn't ever really grieve the relationship itself, this is the first time in 5 years I've genuinely been quite upset!

What is it that you actually have the issue with? If you'd been with a partner for a few months, and your child knew that partner as they were always there then I'm not sure I can see what the issue is?

I think I guess I just feel it's inappropriate to insert yourself into their lives so much after such a short time together

Clearly it hurts from the perspective you’re looking at it from, which seems to be that these are “your” friends and this would have been the sort of event you’d have been invited to in years past, and that’s understandable; but view it from her perspective. She isn’t going to be thinking about you and even if she did she’s very unlikely to be imagining for one moment that you’d be upset or think that she’s doing anything inappropriate. Which isn’t unreasonable, why would she? She only knows that you and Ex-H have been broken up for five years, a long time, and that you were the one who left him. It won’t have crossed her mind to analyse any deeper. She’s not “inserting herself” into the life which used to be yours, she’s just meeting her boyfriend’s friends.

I do see your point, although they aren't his friends, he doesn't know them and wouldn't be able to name any of dc's school friends, he didn't know about the party until I had to remind him for the 10th time the day before, as usual for every party i buy the presents and I sort everything out. So perhaps my issue is him putting on the front of wonderful dad and happy families when he doesn't even brush their teeth, ever done any homework, clean their clothes (the list is almost endless!)

It’s totally fine to be annoyed with your ex for that. You know he’s useless, and that’s part of why you left him. I wouldn’t worry too much about any of the people at the party thinking he’s dad of the year: if they’ve barely seen him in years and he doesn’t know any of DC’s friends, it’s going to be pretty obvious this isn’t his usual rodeo.

I'm not sure from what you've said that your issue is really with the girlfriend. She probably went along to keep him company because, well, kids' parties are really boring. Odd for 2 adults to attend a kids party though...

Is the issue more that you do all the day-to-day work for the DC, you manage their lives, you have the relationships with their friends' parents, you even buy and wrap the bloody gift and stand over your child and make them write the bloody card? And your ex just turns up, takes them and takes credit for all your hard work?

If so, I wouldn't worry. The other parents will work out very quickly what's what. It's abundantly clear at our school which parents are actually involved in their children's lives and which parents just turn up and stand like lemons occasionally.

Yes, perhaps those things! I do everything for the dc, which in all honesty I don't mind because it's for them, but he does tend to think he's dad of the year but with no credentials to show for it!
He is also very controlling of my life, we've been together nearly 4 years and waited 2 years+ to introduce the dc to him, this was partly because of ex h throwing a fit about it and making my life very difficult!

And no my issue isn't with the girlfriend! The dc's really seem to enjoy her company and I have no issues with her specifically at all, in fact I wish I could warn her to run...! If she knew some of the things he'd done over the last 6 years she would think twice about their relationship for sure!