How to explain why we can't see one part of my family

I'm not going to go into too much detail but I have enough evidence that suggests a mid20s male in my family has inappropriate sexual ideas about young girls (there may have been contact as well, but this is all based on he said, she said stuff). This year we were supposed to see that side of my family because he had moved a few states away. When we pulled into the driveway, he stepped out of the vehicle next to us so we pulled a 180 and left. We didn't even get out of the car.This culminated in my daughters' both being extremely upset and they didn't understand why we weren't staying. I felt like a piece of shit the whole ride home because they were so excited to see everyone and while I know I did the right thing, they were pissed at me.I don't want to lie to them. But I have no idea how to explain that we will not have contact with them due to the risk they may be molested or worse. For context, they're both special needs 6 year old twins (Autism and ADHD, speech delays for both as well) and special needs kids are four times more likely to be sexually abused than children without disabilities. I cannot and will not take the risk based on everything that I know.How do I explain this to them in a way that they understand but also doesn't terrify them? via /r/Parenting http://ift.tt/2zmVQYD