As a bit of back-story DD's father left me when I was pregnant and has nothing to do with her. He has recently begun to acknowledge that she is his daughter after previously saying she couldn't possible be his but hasn't requested contact with her. His parents do see DD and have done since she was born although they live several hours away from us. Contact was one day a month and they had a few unsupervised contacts however they broke my trust and I'm concerned they might arrange for DD's father to meet them when they have her. The current agreement is they will see us one weekend every 5/6 weeks but with me in the nearby vicinity the whole time.
My DD turns one this weekend and my parents are hosting a very small gathering for her at their house - my parents and siblings will be there along with a small number of my friends and their DC. It is going to be a very low-key affair and, aside from the fact there will be birthday cake and presents, I don't anticipate the day being very 'party' like.
I have not invited DD's paternal grandparents and they are due to see us the weekend after her birthday. I previously told them that I was not having a party for DD (which was the truth at the time) however my parents have since arranged this gathering. Unfortunately a friend of mine commented on something I posted on facebook with something along the lines of 'looking forward to seeing you on Saturday for [DD name]'s party - can't believe it's been a whole year.' DD's grandmother saw this and has sent me a message saying how upset she is that I lied about having a party and have not invited her.
I replied and explained that it isn't a party but a very small gathering and was arranged after I last spoke to them. I assured them that we could have a special day out the following week to celebrate her birthday wit them. I have had another reply saying I am being very unfair denying them the joy of seeing their granddaughter on her actual birthday and that I'm putting my parent's relationship with my DD above their own relationship with her.
I really do not want to invite them. My parents and friends all hate my ex and, by extension, are not massive fans of his parents. Before leaving me he tried to pressure me into an abortion and said he hoped I'd miscarry and on one occasion he threatened me. I have told his parents this although they haven't really acknowledged it. Their presence would turn what, hopefully, will be a lovely, relaxed celebration into something no doubt stressful and tense.They live hundreds of miles from my parents and would need to travel down so just popping around for a bit before/after the gathering isn't really a possibility.
I really feel that I shouldn't invite them but I don't know if I am being selfish and letting my poor relationship with them (and their son) cloud my judgement. My family very much feel I shouldn't invite them but my mum has said she will support me in whatever I choose to do and welcome them if necessary (they have met a few times previously when ex and I were together) but I still really, really don't want them there. AIBU?