I'm going to try to be brief but I could use some opinions on this:
My sister was sexually abused by a family member when she was young. Our family are very religious, which is relevant. She has disclosed the abuse as an adult to our family, she doesn't want police involvement because she can't face it and feels her recollection as a child is too hazy with big gaps, which is her choice. She's had a really hard few years coming to terms with it, getting counselling, and basically done all she can to get well. She's in her thirties now, married, kids etc.
I have supported her wholeheartedly, as have a couple of other family members. Our parents have however not been supportive. They found out a few years ago but continued to see him and his wife who are elderly. The wife has since passed, but despite indicating when she died they'd cease contact, they continue to see him. They know him to be a violent and nasty person, he has mistreated them all their lives and every other person in his path, he verbally and physically abused his wife until she died (which was their reason for seeing them whilst she was alive, for her sake type thing).
They still feel that they have a "duty of care" to him in his old age despite not doubting my sister, (or so they say). This is where the religious bit comes in. They hide behind it in my view and use it as a shield. They won't go NC and now I feel that I don't want to see them anymore and my sister feels the same. How can we reconcile them seeing him and carrying out their so-called duty knowing he abused their daughter?
WIBU to cut contact with them on the basis that they have not and will not stand up for my sister and think she and I should basically let it go and play happy families? I'm very close to my sister and have looked after her more than my parents ever have throughout our lives and I feel so strongly that this situation is wrong.