Difficulty with my partner understanding our autistic son.

Hello everyone my name is Gemma and I have an 8yr old son who has a diagnosis of high functioning autism.  We had the diagnosis over a year now and I feel like my partner who is my sons dad just doesn't get the diagnosis or just can't accept it and it's causing so much friction and I don't know how I can get through to him.  It's really hard most days to see how he treats him and I find myself stuck in the middle as he cannot seem to change or adapt around our son when situations pop up. 

Any advice would be greatly appreciated Pray