I don't know what the rule is for being friends with the ex, but it's working well for us. We all sit together at the boy's soccer games. I would prefer this over sitting on separate sides and making the kids run back and forth. She is a wonderful mom and we really enjoy each others company.
There are some uncomfortable times when there are references made about events or people that are from their past. But, it's only as uncomfortable as I allow it to be. No sense in pretending like they didn't have a life together.
She's wonderful! Because of her willingness to walk away from her marriage, Tage learned so many things that he wouldn't have without her sacrifice. I'm so grateful for the man he has become, and he wouldn't have become who he is without her ability to stand up for herself and make the hardest decision a wife ever has to make.