Kindergarten to college our kids are graduating from school.
It is really important to keep your focus on your children. This is their moment. It is important for them to have both of their parents, grandparents siblings, aunts, uncles, etc. at the celebration and in the pictures.
I look back at my eldest son’s graduation pictures and see that he does not have a single one with all of the family. There are two sets, one with mum and the other with dad. So sad that at the time my X and I could not see the bigger picture and do this for our child.
Despite all the angst you may be feeling try to put your feelings aside for the few minutes after the graduation, smile in the pictures and give your child the memory.
If things are very difficult between you and your X may be able to bow out nicely from attending a family gathering if being there will make it uncomfortable for your children or your X. If you are having the gathering make sure you ask your X to attend, and his side of the family.
As hard as this seems now, it will be worth it for the memories it will create for your children.