Controlling and insecure

My best friend treats her partner like garbage!! I just can’t even believe how insecure she is, I have confronted her so many times about it and told her how wrong it is but she doesn’t listen 🤦‍♀️ when they’re out in public and another girl walks past he has to put his head down or she will carry on, if they’re watching tv and a good looking girl comes on he has to look away, god forbid if there’s nudity or a sex scene she will turn off the tv and cry because ‘he saw another girl naked’ 🙄 she has full control of his phone and Facebook, she even set up a google account that he has to be signed into so she can see the search history from her phone incase he’s watching porn 🤦‍♀️ he did cheat on her when they first got together and got the other girl pregnant, but it’s been years! Get over it, every chance she gets she brings it up. She even went as far as cheating on him (mind you she was pregnant with his daughter) because he did it to her so apparently it’s justified 🙄 He’s not allowed to go out without her, they’re together 24/7. If I am over at their house she watches him like a hawk and if she goes into another room he has to follow her 🤦‍♀️ not like we would do anything. I feel so sorry for him!! I know it’s his choice to stay but if he was to leave she would keep the kids from him, poor guy. She also gets physical with him when she doesn’t get what she wants. I know he wouldn’t be the only one going through this either. Regardless of how much I speak up for him and tell her how wrong it is she just brushes it off and tells me to stay out of it. It’s just abuse!!