A family nightmare

This is a very distressing topic for me so please be kind.

My step father is for the most part a wonderful man who I respected a lot and was a large part of my life growing up.

When my sister was a teenager he inappropriately touched her breasts, she was embarrassed and didn’t know how to deal with it so closed up. My mother and him broke up for a while, he was extremely remorseful and eventually they got back together and married, swept everything under the rug. My sister refused counselling cause she was embarrassed, she was 16.

Some years down the track he also inappropriately pinched my bottom, I was a teenager and also had the same reaction to my sister. My mother was not informed and it just went away. He apologised.

Now they’ve been married 17 years and we have recently learned that he also inappropriately pinched my other sisters bottom only last year and made her feel extremely uncomfortable with strange conversation about how amazing and beautiful she is. She is in her 40s!

My sisters have decided they want nothing to do with him anymore because they are concerned for their children’s safety, he has previously bathed them and had a very very close relationship, he’s considered their grandfather.

My mother believes in redemption and wants to pursue their marriage but it’s having a harming affect on us sisters. I don’t know whether to try and have some sort of relationship with him for my mothers sake or to cut him off. It’s a very complicated situation because my mother is not young, she has retirement in her near future and I don’t want her to be lonely and depressed. I worry she will also resent us if we cut him off.