Blue is right. By remaining quiet about what he's done, you're enabling him. Them being together for 10 years, clearly doesn't mean anything to him. You don't wanna ruin a relationship that clearly is already broken the moment he did whatever he did to you.
I hope you see where we're coming from here. Your first priority is to keep yourself away from the guy (stay safe) which you have done. Next is to warn the gf as she is your friend. If she doesn't listen, you've done your part. Cut the contact, for your safety.
If what he did is not as bad as we think, then, no big deal. There shouldn't be a need to go out of your way to avoid them.
I hope you see where we're coming from here. Your first priority is to keep yourself away from the guy (stay safe) which you have done. Next is to warn the gf as she is your friend. If she doesn't listen, you've done your part. Cut the contact, for your safety.
If what he did is not as bad as we think, then, no big deal. There shouldn't be a need to go out of your way to avoid them.