OK, to start.. my bfs children were taken out of his home for an accident that didn't even happen while in his house, let alone under his care. Him and his wife were still together at the time. They separated and he got court ordered visitation. Everything was going fine, except when the woman who has custody would throw up some bogus accusation. It even got to where we were keeping them extra nights, because she needed us to. Then out of the blue, she moves 2 counties away. We are not able to reach her by phone, when we FINALLY got her address, we started sending birthday cards and other holiday cards, but those always sent back. Well my bfs mother got her back in court for visitation for herself, which she got. Well my boyfriend and myself went for the first visit and she found out about it and threw a fit. Now she is starting up with accusations once again, and she doesn't want him to see the kids, but is letting her daughter see them(who is a criminal and is on the run)... what should he do?

He should get into court and have his visitation enforced.

What kind of accusations are they making ?

ok, to start off..my bfs children were taken out of his home for an accident that didnt even happen while in his house, let alone under his care. Him and his wife were still together at the time. They seperated and he got court ordered visitation. Everything was going fine, except when the woman who has custody would throw up some bogus accusation. It even got to where we were keeping them extra nights, because she needed us to. Then out of the blue, she moves 2 counties away. We are not able to reach her by phone, when we FINALLY got her address, we started sending birthday cards and other holiday cards, but those always sent back. Well my bfs mother got her back in court for visitation for herself, which she got. Well my bf and my self went for the first visit and she found out about it and threw a fit. Now she is starting up with accusations once again, and she doesnt want him to see the kids, but is letting her daughter see them(who is a criminal and is on the run)...what should he do??

I'm really confused on a lot of things. You need to start using names, or even something generic like a letter or number, to identify each person. So far, I've counted 4 different people involved in your story - not including the child(ren) - and I have no clue what you're even asking.

Why is your boyfriend's mother, the paternal grandparent, defending his ex-wife? Or did you mean HER mother, the maternal grandparent, went to court to get visitation and is now letting her daughter, the mother, see the children?

What does the court order currently state? Does your boyfriend have sole legal and physical custody or is it joint? Does the mother have visitation rights, supervised or unsupervised?

First, when she moved, without telling you where or providing contact information, she committed parental kidnapping. As soon as the father (your bf) found out where she was, you should have reported it to the police. He should have also gone to court to have her cited for contempt for violating the visitation order.

I would get an attorney, with her actions he might be able to gain physical custody of the children.