I agree with the others as far as telling his parents ... not your responsibility. I wouldn't hide it if you talk to the and they ask, but I don't think you should go out of your way to inform them.
As to your insurance ... if your job and benefits are anything like most, you probably can't take him off your insurance unless it's Open Enrollment period right now. They only allow changes to the insurance during that time of the year, or if a significant change has occurred, such as death, divorce, he got individual insurance that would be primary.
I am relatively new here, so I don't know your past threads about this situation, but you can only control yourself and how you react to situations. And I am learning that it's better to be PRO-active rather than RE-active. My recommendation is to sit down and think about what you want out of life that you can actually control, and then do what you have to do to put that into action.
My RABF and I broke up a couple of weeks ago over me telling his mom that he had relapsed. I *think* I am doing what's best for him, and for his mom since he is staying with her right now, but it wasn't my situation to butt into, and I have realized that. I'm still emotional over our breakup, even though I *know* without a shadow of a doubt that he is not the right type of man for me. I can't help still loving him and I miss him being a regular presence in my life ... although I can't define why.
As much as it angers, frustrates and hurts you, you have to make the decision based on what's best for you and your children.