Ex / Children’s dad- Complicated - Long

Warning DV & Miscarriage mentioned

I have 4 kids, 2 of which share the same father. However, My daughter has never had any kind of parental relationship with him although he would say hi to her, sometimes buy her and my other children Christmas/easter gifts.(She is the younger of the 2)

However, My son has had a relationship with him his whole life. Would pretty much see him every weekend or every second weekend.

I was a young mum, a naive teen who should have listened to her mum and stayed away from this person.
We had a relationship full of ups and downs. I had a miscarriage and was so terrified I dealt with it horribly and alone.
I then became pregnant with my son and was too afraid to tell anyone I forced myself not to believe it and didn’t get a scan til I was 20 weeks.
Time passed I had my son and loved being a mum, we split up and whilst things weren’t great I tried my hardest to keep the peace and eventually I became pregnant with my daughter.
Things went downhill. He demanded I get an abortion and I felt alone so I agreed until the night before when I burst into tears and finally broke down and my mum said “ you know I will support you, don’t do what anyone wants you to do, do want you need to do”.
I decided that was it I needed this baby!
Well, long story short my house was smashed up, my life was threatened and my mother protected me.
We went to court and I had an avo until after my baby girl was born and we were safe enough to learn to co-parent my son.
Jump to 2024… whilst we had some disagreements over the years I had worked my butt off to no not only forgive him but hold genuine respect for him. My daughter has a dad in the form of my beautiful husband who I met when she was a baby. My son had his time with his dad.
Whilst this wasn’t perfect I had done my best to move on.

Then one day, I go to visit him at work to pick up some papers for my son. He’s acting strange.
Tells me now my son is old enough to drive and have independence he’s excited to not have to talk to me. ( I bit my tongue)
Then tells me his girlfriend (who has no knowledge of my daughter) has the best nickname for me! I won’t say it but it is because I should be dead to him. (Wtf?) I faked a laugh walked away and haven’t spoken to him since.

AITAH for not talking to him?
He has not made any attempts to contact our son, even all through Christmas and New years and it’s been months.

My mum keeps telling me I should just call him and encourage him to call my son but I don’t want to. I have told my son everything, I have told my son my thoughts but have said “ you are old enough, make your own choice and I will support you” even offered to drop him at his dads work… my son is angry, upset etc with his dad but pretty normal emotionally every day.

My reasons for not talking or encouraging the relationship to be sorted are:
1. It’s not my job, their relationship is between them.
2. I fear what impact the relationship could have on my son as a soon to be young adult. (Dad and grandpa are both alcoholics)
3. My son is very gentle and very different to his dad and I fear he won’t be able to set boundaries with him once he does turn into an adult if I force a relationship now.
4. I have asked my son a number of times if he wants me to do x,y,z. He tells me no.
I feel I am disrespecting his boundaries if I do anything.

AITAH?