One year our family Christmas was hosted by my aunty and her second husband. among the guests were her first husband and his partner at the time, as well as his mother. It was different, but it was certainly good to see that even after a marriage break down, some people can still be civil with each other.
Move forward to now, and my ex's Mother (who openly hated me to start with) still sends Christmas cards to my Mum and family. We didn't have kids, or even get married, but were together for 15 years, and are still friends.
It's always good when people can work together even though they can no longer be what they were for each other.
I LOVE this! This is how it should be.