It’s always frustrating to see responses like yours where you project your life and experiences onto someone else and act as if it‘s the word of truth. His girlfriend’s life, beliefs and values are obviously different than yours so you going on and on with the other commenter as if your way is right is quite ignorant. Good for you and your ex-fiancé, that’s amazing and I’m being serious. My uncle’s ex still comes for holidays with his current wife. It’s amazing and we all love it. But, guess what? That doesn’t work for everyone and they aren’t wrong. I know just as many people who have boundaries with exes than I do those that don’t need them. Everyone is allowed to choose their boundaries.