She punched him at an elementary school

My fiance and I are going through a huge custody battle with his son's mother. She actually witnessed her son (7 years old) get hit by her boyfriend and she stuck up for the boyfriend.

She has temporarily lost rights to their son. We went with her to their son's school so she could give him a hug because she cant see him for a while. I stayed in the car to respect their space, but I watched her attack my fiance. She punched him in the face right in front of their son and in his ELEMENTARY SCHOOL parking lot. I instantly got out of the car and called the cops.

My fiance is actually really, really mad at me for doing this and is saying I'm ruining her life and he's making it seem like he is only concerned with the fact that now she is in trouble. This is not the first time she has attacked him like that either, but he let's her get away with it every time.

I'm so upset. I was just trying to protect the man I love