My nephew is 5 and is ASD, and very violent and aggressive. He hits, bites, punches and scratches my son who is 3 CONSTANTLY. It's really starting to get me down that each time we visit, I know my son is going to be hurt. It makes me not want to let them play together anymore, but my hubby feels guilty as this would really upset his sister (she tries her best to control her son but nothing works). I need some advice on what to do, as I can't carry on seeing my child being abused.