To stay in touch with and occasionally see your ex's family. I mean 1-2 times per year or something.
Broke up with him years ago, no interest whatsoever in him no communication at all for years, but his family were like a 2nd family to me, took me in and treated me as a daughter, even after the break up we stayed in touch, lost contact for a while but have been in touch since and they would like to meet up Covid permitting.
However feel that this may be disrespectful to my current partner, the ex has never been there when I go, he wasn't a nice guy and i've zero to do with him, I see his family as my own friends.
Would it be wrong to meet them again ? Fine to be told it's out of order.