I separated from my ex partner who then began dating my best friend for a short while and they are now pregnant with his child. My ex wants nothing to do with this child, so has decided he isnt having any involvement, he no longer talks to my friend who is due to give birth soon.
My ex had said he is not telling our child about their half-sibling and that I have no right to tell them either - our child is 8, he plans on them never finding out. However, I have numerous other close friends who know about the baby and their children know about the baby and the pregnant friend lives a very short drive away. I'm fearful for our child's mental health should they find out through someone else or through another child talking about it to them, as I feel this is likely. I have said to my ex that they need to tell them due to my concerns of someone else telling them and the betrayal they might feel because of it. It's breaking my heart for our child because I feel they should know, I don't want them to feel I've hidden something from them but their dad won't allow me to. He has been emotionally aggressive and physical aggressive in the past, no physical harm to me or our child but has hit things in our home, which is why I left the relationship which makes me worried about telling our child when he's saying no.
Please can someone offer some insight or advice, any thoughts or opinions would be much appreciated.