Since bottom lining it evidently didn't work the first time, let's try again.
Can court order force son to miss football pictures?
Yes. The court can force the son to miss the football pictures. If the pictures are to be taken when it is Dad's time, and the parents are not sufficiently grown up to manage this issue themselves, the court is not likely to decide that having their picture taken with the football team is more important than spending their time with Dad. The court is also not likely to be very happy with parents who are unable to come to an understanding between them and need the court to micromanage them. But Dad is on firm ground here. Mom (NOT STEPDAD) needs to either come up with a workable solution that Dad will accept, or Mom and Stepdad need to accept that Kiddo is not going to be in the football picture.