Maybe it's a generational thing...

A long, long time ago, I had a falling out with my cousin.  At the time, she was living with my grandmother and even though my grandmother tried to be fair when possible, for a while, she clearly took a side - and it wasn't mine.  As time went on and things were back to being good between us, any time we talked on the phone, she would mention my cousin.  Not "You should call your cousin" or anything like that, she just found a way to insert my cousin's name in to the conversation like "Oh, so-and-so did this" or "So-and-so went here".  Honestly, I could have cared less and I wanted to say to my grandmother that I really didn't want to hear what my cousin was doing, but I kept it to myself.

A couple of years ago, Frank and I had a falling out with one of his relatives.  The whole family was aware of it and this person pretty much bad-mouthed us to anyone and everyone that would listen.  Clearly, his parents knew of this but they try to be like Switzerland and stay neutral.  But in the last year or so, my mother in law has been constantly bringing this person in to our conversations.  At first I thought it was just me over-reacting (imagine that!) but clearly, each and every time I talk to her, she tells me what is going on with this relative - like "Oh, so-and-so called me the other day" or "Oh, I just got off the phone with so-and-so".

Really?

Why do I need to know this?  I am a good conversationalist.  I am pretty awesome at keeping a conversation going without people having to bring up individuals who are no longer a part of my life. 

When I mentioned this to Frank recently, he got really, really angry and was like "The next time she does that (meaning his mother), give the phone to me!"  I have not.  I don't feel like he needs to yell at his mother over this but then again, there is no nice way for me to say to my mother in law that this relative of hers is essentially dead to me and I don't want to hear about her ever again.  

How do you stop the awkwardness??