Wedding with partner and the ex wife problem

My partner's nephew is getting married in 4 months and this is causing problems!! His daughters mother - his ex wife - knew his family for 25 years and the problem is that we cant both be at the wedding (I have reached out an olive branch to her to meet etc but she has refused) He has basically asked me that if it comes to it that I 'step back' and take the moral higher ground for the sake of the girls, as they will be upset if their mother cannot be at the wedding, but I suspect if she said to them it wasnt a problem we wouldnt be having this problem. I told him I was now his partner and it is HIS nephew getting married so surely I would be asked. He said probably but most likely she will be too and one of us has to back down. After other issues as mentioned before re his daughters and their mother,I am exhausted and furious. I would step back for the sake of the girls but am tired of it all, and angry that it should be me to step back when I am his partner! have we any hope? and can i really end an otherwise good relationship because of a wedding ... but it is the principle and I have not yet been to any of his family weddings (we were in a distance relationship for 2 and half years and have lived together now for 5 months). Am I wrong in thinking that any new partner - whether man or woman - would want to or accept to stay away from the current partners family wedding so that the ex can go..!??

Put the internet to work for you. via Personal Recipe 2629979