Yes it happens, sadly. Yes they have the right to file for visitation, but that doesn't mean the court will grant it. I think that it should be the parents discretion...for instance my kids have never met my mother and they never will if I have any say over it. My MIL is no longer allowed to see my boys (unless she accepts our daughter). Both lost the right to see my kids because of their actions (and the fact the my mother is a horrible mother and human being.)