Worried about my Ex finding out I’m pregnant

Sorry long post but would really appreciate some help!

Hi all, just looking for a bit of advice and reassurance. I am currently 9.5 weeks pregnant with my second child. I have a 7 year old son from a previously relationship. My ex and I separated when my son was 2 years old (Feb 2020- just before Covid / lockdown hit).

My break up was absolutely horrendous. I saw a completely different side to the man that I’d spent nearly 13 years of my life with. We mutually decided to end it as we were both unhappy but he quickly tried to backtrack a few days later, but because I stuck with it and refused to continue the cycle of unhappiness, his behaviour changed instantly. We were stuck living together for 6 months as we were unable to sell or move out because of Covid restrictions and closures. In that time, he made my life a misery and completely broke me, was verbally abusive and shattered me mentally and emotionally. I ended up signing over our 3 bed house to him and moved into a 1 bed place with my son as I just couldn’t take it anymore.

He was never a good partner and treated me terribly, but like an idiot, I put up with it. When I fell pregnant, he promised me that he would pull his weight and become the partner and dad I needed him to be, but he never was. He chose to take on overtime constantly because it was “easier to be at work than at home” as he found being a dad really hard and hated my son climbing on him as he “just wanted to relax”. If he wasn’t at work, he was down the pub. I could never rely on him for support or guidance and he was a terrible dad.

I started getting close to a work colleague a couple of months after we split and when Covid restrictions started to lift, we began spending time together and got really close. We quickly realised that it was becoming serious and a year and a half into our relationship, we moved in together, and in March 2024, we got married.

I am the happiest I’ve ever been and I am really looking forward to having another child. My worry is how my ex is going to behave when he finds out.

Since we’ve separated, he tries to act like he’s dad of the year and constantly criticises little things I do and makes little digs when it comes to my son. (Coming from the man who didn’t bath my son until he was 3) He always acts like it’s a competition and constantly tries to undermine me. He is extremely childish, petty and pathetic.

He badmouths me to anyone that will listen and tells people that I cheated on him with my husband (which I didn’t). When my son would mention about our wedding he would say things like “stop talking about it to people because no else cares other than your mum”. So my son stopped talking about it to anyone, even though he was really excited.

I’m worried that he is going to say nasty things and try to drip poison in his ear when he finds out about the baby. Try and make him not look forward to it in the hope of manipulating him to want to spend more time with him.

When he has my son for more than a few days, my son often asks to come home as he struggles to be away from me and his dad gets really angry and accuses me of being the reason he doesn’t want to be with him, which is completely untrue.

I’ve even chosen to tell my son about the baby after Christmas when I will be 14/15 weeks because I don’t want him to mention it to his dad whilst he’s there over the holiday period and his dad to go into a mood and ruin Christmas for my son.

Does anyone have any advice on how best to manage it if he does try to be spiteful when he finds out and to keep it an exciting time for son, regardless of if his dad tries to spoil it?