Hello everyone!

My grandmother (who is really more like a mother to me) doesn't like my future hubby and is refusing to attend our wedding. I've accepted this, but I'm wondering how to delicately handle this during my shower and wedding--so far I've avoided saying anything about it to the other side of the family and my friends. I don't want people to think she's a big jerk.
What would you say to people when they ask why grandma isn't there?
Thanks!