u/Ambitious_Map_7790

On Saturday, I threw a birthday party for my son at a local indoor soccer complex. My son had invited his friends from school and his soccer team. My mom and husband also came. Within 15 minutes of the party starting, my son’s father (my ex-husband) unexpectedly arrived. My husband was out on the field kicking a ball with the kids, but when my son’s father joined them, my husband noticed him and stormed off the field. My husband told me that he was leaving because my son’s dad shouldn’t be there because this was our party (I solely paid for it). My husband grabbed the keys and left, continuing to tell me that I need to make him leave. I told him that I hadn’t invited my son’s dad, it must have been my son. I was unaware that he was even coming, and I don’t believe I should have made him to leave. My husband and my son’s dad have never had any issues, and my ex-husband and I make an effort to get along because of my son. My husband is not telling me that I choose my son’s dad over him because I didn’t make him leave the birthday party and let my husband leave instead. AITA for not making my son’s dad leave?