Step kid missing birth!

Has anyone had to deal with a step child being gone when the baby is born? My step son is most likely going to be gone when we have the baby. He's going to be in Oklahoma for a month with his mom's family. My mother in law is trying to make me feel quilty about it, but there isn't much I can do if he isn't going to be around. I just want to know if anyone else has had to deal with a situation simular to this. I hate that he may miss it, but I also don't want anyone in his mom's family bringing him because I don't want them around me!