What I don't understand is why the parents are so offended by this even have their children attend that school. Surely they will see the teacher in the halls or somewhere on the school grounds. Oh, the horror! Their babies will be exposed to seeing something the parents disagree with.
They should remove their children from school altogether and send them to a monastery or, better yet, homeschool them so they can be brought up in the proper bigoted environment they desire.
But if they do that, then they couldn't sue anybody and hope for thousands of dollars in settlement income.