DH and I are very concerned as DSD told us at the weekend that she saw bitemarks on her Mum and that her Mum has said that her DP has a problem with bad dreams and he sometimes hurts her when he is asleep. This includes biting, punching and headbutting, apparently he dreams that he is a
Vampire/wolf 
We were and are both very concerned so DH asked to talk about it with her mum and he was told to "fuck off and mind your own business". This made us even more worried so he tried again and got the same response. We called the NSPCC and they said to call social services. We weren't keen but didn't see any other option. They have said they will look into it. DSDs Mum has now said that i am not to collect DSD from school as I would normally do.
Please help, any advice appreciated.