It has been smashed by poor judgments, nasty words said in rage, or overreactions—sometimes by the parent, sometimes by the grandparent. It's a given that grandparents who have a good connection with their parents have access to their grandkids; grandparents who don't normally don't. In most states, if you're married to the child's mother, she gives you permission to have contact with the child. If you're not married to the mother, then either she gives you permission or she doesn't. Some mothers may prefer that their boyfriends or husbands not have contact with their children, but they can't stop them from seeing their grandchildren. If the mother doesn't give her husband or boyfriend permission, then he can't take her to court for denying him access. He can still see his grandchildren whenever the mother takes them out or allows him to do so. If the father of the child is married to another woman when he has children with his first wife, then those children are also entitled to support from their grandfather. The father can't refuse to let his daughter-in-law see her children, but he can't take them away from her either. She might not want her husband to have anything more to do with the children than just see them when he takes them out for visits. If the father isn't married to the mother when he has children with another woman, then he has no legal right to see them.