There will be occasions where they have to attend together such as birthdays for the kids, communions (if they are catholic), children's events like soccer game, competitions, weddings and to some extent family holidays.
She may not be sharing a bed with him, but she still shares his life which means no matter how much you want it to just be two of you, it will always be three of you, regardless of whether she is in good or bad terms with him.
So when your divorced partner introduces you to them, they will not welcome you in their circle.
They will smile and say hello to you but that’s it.
At first this may seem okay to you but gradually you will get frustrated with their constant communication, even after he tells you they are only discussing the children.
After their divorce, those mutual friends tend to choose one of the divorcees, which is most likely the wife.
When you are in the infant stages of dating, this may not seem like a big deal to you, but gradually this will become more and more apparent.
When you first started dating, he was available at your fingertips, even on Monday morning for a date.
His kids will see you as proof that their parents will never reconcile.
His friends will find it hard to associate you as his new partner.