AITA for being upset for my ex ditching our sons sporting events?p

Is it petty of me or wrong of me to be upset with my sons father for missing yet another sporting event of our sons for a girlfriend’s family get together? Our son is in soccer and football this year and he’s already missed the first soccer game and now is going to miss his first ever football game which is on a Saturday at 9:30 in the morning. He told me they decided last minute that they are going to get a hotel and plan a whole weekend where family lives. He knew about our sons first game before they made last minute plans. Plus this man is possibly looking at prison time of a minimum of one year up to 10 years for some stuff he has done(none that would hurt our son) so this may be the only times he will be able to see our son play his games for a very long time or even ever depending on if our son wants to do these sports again in the comigg be years. I’m just upset because I feel he’s choosing a girlfriend over our son and our son always asks if his dad will make it to any of his practices or games and his heart breaks when I tell him not this time.