If it were me, I’d frame it around the past being exactly that, how happy you are with the present and how what’s been and gone doesn’t matter. I’d want to make it as non-confrontational as possible, while still making the point that I don’t want to know.

If that makes sense..

I don’t think that anything positive comes out of these discussions, for anyone, ever!

You’ve already alluded to how it could cause issues, so unless your intention is to cause an issue, I’d avoid it.