How you talk about her OH not knowing she had an abortion is a bit disturbing, as if you have fantasies of somehow letting him know, and fucking up her life.
And no, I'm not an ex-wife or anything.
But then as soon as I say my opinion on her he stands up for her.
Don't do it, then.
Treat DSS reasonably yourself, as you presumably are. That's all the involvement you have to have in any of this.
I think PP's are right, counselling would help. I got counselling because I was wound up about something/someone, and I think it's helped. You could see a counsellor to let off steam, or a therapist to help you deal with this situation. You'd feel better for it.
Then he will say something like ‘well she wasn’t ever maternal’ I’ll say well why did u have a child with her? Then he gets annoyed at me
If you say this, you're not criticising her at that point, you're criticizing his judgement in having a child with her. Of course he's going to explain his choices and be defensive then.
But then when I say that he goes in a mood with me saying so u think it’s ok DS is hysterical not wanting to go etc.
Do the broken record method. 'I'm not getting involved in your co-parenting...I'm not getting involved in your co-parenting....I'm not getting involved in your co-parenting.' Don't engage in discussion.
The whole scene sounds like it must be unpleasant to live in.
How do you feel about the relationship in general? Does all this aggro take up much of the time? What are you getting out of the relationship?
As a PP said, this is still quite early in the relationship. It doesn't sound a barrel of laughs TBH.