California Grandparents Rights
Statutes Amended in 2007 to Include Stepparent Adoptions
See More About:grandparents rightscaliforniafamily issuesCalifornia grandparents cannot file for visitation rights while the child's parents are married, unless specific conditions are met. These condictions include the following: the parents are living separately, a parent's whereabouts are unknown for a month or more, the child has been adopted by a stepparent or the child does not live with either parent. In addition, a grandparent may petition for rights if joined in that petition by one of the parents.
Visitation rights are based on a pre-existing relationship that has "engendered a bond." The court is also directed to balance the interest of the child with the parents' rights and authority to make decisions about the child.
In 2007 the California laws were amended so that grandparents do not lose their rights if a stepparent adopts their grandchild.
See the California statutes about grandparent visitation
Being a foster parent actually does not have anything to do with grandparents rights, but wanted you to see this law for their rights for california. The promlem you and your son have here is although he raised his girlfriends son, because he is not the father he does not have any legal rights, and to be honest how he raised him all this time and not being the father is beyond me, usally when ever a child gets at the age of school, a birth certificate is required, and custody order. Maybe if your son talks to her she may consider allowing you both vistis, the least she could do when letting him take care of the child all these years.

