Question about ex relationships

My boyfriend is bothered that my ex husband and I made arrangements to see our son’s college play. He will pick me up at the airport and we will drive 4 hours to the university. We will stay in separate rooms in the same hotel and drive back to his place for 1 night where I will sleep in another room before going to the airport the next day. Overall, it’s a weekend trip with whom I see as a great friend still, and we are seeing our sons play together. Is this wrong of me to tell him after the plans were made? I don’t think I did anything wrong here, and told him the day the plans were arranged.

Td:lr-is it wrong to be friends with an ex?