I f 30 have a son 8m with my ex 33 m. He has a wife of 2 years now. We coparent as best as we can and I involve his wife into almost everything doing with our child. The issue is there is one thing that I do not want to share with her and it is my son's first mother son dance at school. I feel like if it was a dad son dance or something similar I wouldn't push my partner to be there with him and his father because that's special bonding time not meant for a bonus parent but the biological parent. This is where I'm feeling like the ah is he before even taking to me called the school to see if she could also go and share the moment they said yes which then they both assumed it would just be okay because of the school.. They have brought it up that it also hurts her feelings that I don't want her there for a special moment. Now a little backstory my son is the only living child I have after many failed attempts his first are the only first I will ever get I can no longer have any more children.. they have decided they dont want kids but are both still able to do that if they wish.. I just feel like if she wants special moments like this and to feel as a mother she should have her own children and not try to take moments away because it hurts her feelings.. also my ex and I don't have a good relationship only get along with him for my child and tbh like her more than him and will try to talk to her about our child over him yet I feel as if this just isn't right aitah?

Edit: I have asked my son what he wants on who he wants to go to the mother son dance with him his first response was idk last night.. today his cousin asked and he said he wanted just me. I thought having someone who wasn't a parent have the talk with him on what he wanted would be less pressure and he would say what he really wanted that way.. his father and bonus mom never once thought about asking him.. I should have add that was one of the first things is asking him what he wanted because he does come first.. I said it the way I did to show the problem isn't what the child wants both but me there.. yes i also know i could convince him that having us both there could be a good benefit to him but the issue is I feel like the ah for actually listening to my feelings and emotions also of not fighting he wants just me... Sorry