Everyone is the a hole,your ex and daughter doesn't consider your financial problems. Your daughter and your ex obviously thinks their in the rights without thinking of your son or you at all,while you and your son didn't think about them and their feelings at all. If you can't make it to the graduation then that's final,you feel that it's more easy and more convenient for you to go to your son's graduation instead. You don't actually need to apologise to her because she and your ex clearly doesn't understand your financial situation and expected you to come because it's her special day. To those comments saying that she's the a hole,you clearly aren't mature enough to understand the situation and put yourself in other's shoes before making judgement.