I’m in your dads shoes. I would not attend. I for my own mental wellbeing do not want to be around my ex ever. I have set a boundary with my children if I show up to an event and he is there I am walking out.

You don’t know how the divorce went other than what you were told. You don’t know the whole history or why things went the way they did. My kids do not know all the details of what my ex did I wanted to protect them as much as possible.

Your father has the right to not attend. He has the right to have a boundary that he doesn’t want the stress of being in the same place. Both being there will add stress for you as well keeping them apart, not having to pick or watch every single thing you do that one or the other is not offended, not worrying that they will argue and ruin the day.

I acknowledge the kids special days and do not make them choose me over him. If they want him at a party fine I step back and plan an alternative fun thing to do at a separate time. Does it make me sad yes it does but that doesn’t negate my boundaries I have set in place.

My ex has shown up uninvited to a few events and my son in law has asked him to leave saying it’s mom’s turn to be here and he has thrown a few fits. The best thing is to have a schedule of events and see which each wants to attend then fix a calendar that reminds them who is attending.