I blame the mother. She invited the wolf in because he got her hot and bothered and her kids paid the price for her lust.
The MOST dangerous place for a child is in a broken home with mom’s Boyfriend.
The greatest threat against young kids, especially boys, is "mom's boyfriend". Mom's kids aren't his, and he can see them as a distraction and annoying extra burden.
As mom gets older and her looks go, she is more likely to acquire a boyfriend who mainly wants access to the daughter. Some moms go along, as the price for being seen as having gotten an attractive man.