I think it depends on the friends. My W and I also share some friends. Recently, I got together with some friends we hadn't seen in awhile. I'll have to admit, I felt a little guilty because I really didn't want my W to come along. And we did get into R talk, rather heavily. However, it is a little different in that my W really hasn't talked to them too much.
I think if you are comfortable with your friends taking a fairly neutral stance, I would limit the R talk. I definitely wouldn't put any friends in the middle of the situation. It's not fair to your friends, and it has the potential of being destructive.
