To not want my exes partner at my child's birthday party?

[wherewego]

Prepared to be told I am being unreasonable but I'm looking for some impartial advice on this situation.

Me and my ex have a DD who is 6 together and get on fairly okay for the most part but we do have our moments.

For DD's birthday and for christmas we go shopping for her gifts together and he comes to the house to watch her open them, everything is pretty amicable and he is a good dad.

He has been with his partner for over a year now, at first I found it very difficult especially as I knew of his partner before he got with her. She used to live with my best friend when they worked abroad together and I've heard not very good things about her and I was told these things before she got with my ex so of course I did make judgements based on the information I was given.

Anyway I got over all that, she spends quite a bit of time with my DD and she really likes her. All good. However, I haven't met her and I really at this point don't have a desire to. They've only been together a year this month, they don't live together and aren't married so I just don't see the need to meet her at the moment.

My ex has asked to half in for a swimming party for DD's birthday next month. I agreed. On the phone with ex this morning he mentioned that his partner will be there in the pool with the kids whilst I have to stay out of pool to greet parents and children. I told ex that I didn't feel comfortable with his partner being there and could she step back and they could do something desperately with DD. My ex wasn't happy about this and said he'd think about it. But I had better get used to her being around. The thing that upsets me is he didn't even ask if this would be alright for me. I already struggle with anxiety and meeting parents etc makes me nervous so would prefer to not have to meet his girlfriend on top of that.

So my question is, would I be unreasonable that if my ex insists his partner needs to be there, that I say that's fine but I'm not paying half. I'll step back and let this be there party for her and I will do something separate with my family and my DD?

I feel guilty as it would be nice if I could be there but at this point I just don't feel ready to meet her.

Thanks in advance

Livelovebehappy
Nobody is claiming to be perfect. I think quite a lot of us are struggling to see what feelings need resolving and what there is to be ready for or prepare for when someone has been split for years from their ex, doesn't love them anymore, has no feelings for them, both the ex and the OP have new partners and the ex's partner has been a stable and positive influence in the child's life for a year.
From the worries about jealousy of DC being "my daughter" and the comfortabke co-parenting the OP and ex do regarding Christmas (which may have to change over time depending on what happens with new relationships, potential future children), it all sounds like the OP has feelings of jealousy or insecurity or something else that suggests she's not quite ready to accept putting them on one side for her child. Who knows maybe it's wanting to meet ex's DP when she has her own DP to introduce, I don't know I'm just wondering.

The problem is that it's been a year, so there's a fairly high likelihood that in a year's time these feelings will still be there or there'll be another reason why not to and so it get kicked into the long grass.

Op, your feelings toward ex’s GF are understandably due to how she treated your friend. She may or may not have changed, but for your DD’s sake, I think you should give her the benefit of the doubt.
That doesn’t mean you have to attend the party - but if the GF is going to be in DD’s life long term then you really should meet her sooner rather than later.