Why would he do this?

[Finnyhaddock]

There's a big back story which I don't want to go into but there's a certain topic my DH and I try not to talk about.
He brought up the subject and I swear I didn't and don't do anything to wind him up about it. I was rational and non judgemental.
Every time he accuses me of having a go at him and I know I'm not.
I think it's a type of gas lighting because then I really do lose my temper.
Just why?

What else is he a prick about? I doubt this is the only thing.

Too vague to comment sorry. Be more specific.

So basically he sets you up to get mad at him and then blames you for getting mad? Sounds like he is a head worker.

Do you catch him smirking as if he is satisfied you have got angry? Does he accuse you of being 'oversensitive'?

He's not an abusive person and I am sure he has low self esteem. For him it's a touchy subject as he made a very expensive mistake.
Over the years he has become financially able to put it right but hasn't actually done so.
Basically we split - he bought himself a property at inflated price with a stupid mortgage deal - we got back together and now if the subject is discussed he gas lights me.
I think sub consciously he's trying to deflect his feelings of inadequacy on me. Am I right?
And why do that?

OP please don’t make threads if you aren’t going to give context, how do you expect strangers to be able to comment?

Yes he’s probably embarrassed that he made such a bad decision

But why would you be angry at him? Presumably he needed a home and made a judgement based on the facts at the time? Life is unpredictable. I can’t imagine having anything negative to say if this was my dh so what are you angry about? Maybe he’s bringing it up in the hope of some kind of forgiveness from you?

"I was rational and non judgemental."

What sort of comments do you make that result in this reaction from him?