Ex partner.

Not directly baby related so hope nobody minds this post. I’m due to have a baby with my current partner of 3.5 years in a few days time however I’ve still not told my ex partner, father to my teenage son (14) that I am pregnant and the simple reason being I’m too scared to. We were together for 10 years before separating 5 years ago and during that time he was awful, he was controlling and a abusive bully and still continues try and be that way now but as we barely have any contact due to him just communicating with my son it doesn’t affect me a great deal anymore. Him and my son are close and see each other regularly but he was always possessive over our son and I feared if he knew he was going to have a sibling with no direct links to him that he would completely fly off the handle and I just haven’t been able to face it due to a difficult pregnancy and not wanting to stress myself anymore, I was hoping my son would have mentioned it to him however he has not because he said he doesn’t think he dad will like it. I feel like such a coward and don’t know what to do in order to gain control of the situation because I don’t want my son to bare the burden of a secret sibling it’s honestly ridiculous. The whole situation is bizzare, he has a partner himself the same lady he cheated with 5 years ago yet she’s not a part of my sons life he keeps the relationships separate which I can’t get my head around either. Not sure what I’m looking for, I just feel miserable with it and dreading having my baby. Can’t talk to my current partner about it as he just gets cross and says he couldn’t give a hoot if he never finds out none of his business so that’s not much help.