So, our situation: We are a group of 12-14 friends, mostly couples, people who socialise regularly, some are closer than others. About 6 months ago one couple split up acrimoniously because the man had been having an affair with one of the single women in our loose group of friends. The fallout has been hard, particularly on the female of the (now ex) couple, obviously. He has moved not far away and is now in a relationship with the OW. Since the split he and his gf have kept their heads down, not socialising much, but they seem to have decided to start socialising more. This is very difficult for his ex who can't cope with the idea of seeing them together. Personally, I don't want to socialise with them at all, but I know that other friends feels differently and are seeing them. But this is hard for my friend (the ex) to deal with.
So my question is, what happens in these situations? Should/do friends take 'sides'? Should/are friends 'loyal' to one party and shun the other? Or should you be neutral? With Christmas coming, there are a lot of get-togethers being planned: does just one party get invited? Or invite both and let them decide what to do? I really feel for my friend that she might be put in a situation where she won't go to a social thing just in case they are there - why should she have to stay home?
Thoughts, experience, advice...all welcome!