This happened to me. We met at grief support group, so both of us had a spouse die at about the same time.

He did that too. I did at first but didn’t feel the need after a while. He never stopped and if anything it got worse.

He was one of those types that was extremely intelligent offset by a lot of incompetence elsewhere. He made a lot of mistakes and I busted him.

The reason he did so much talking about the deceased spouse was a deep dissatisfaction about how I was so unlike her.

I caught him in a lie, and the more he tried to defend it, the more pathetic and ridiculous it became.

There were other problems.

I dumped him.

Anyway, I don’t know if your situation is like mine. Give it time and you will figure it out.