It seems like we're afraid of exes. In a way, we think it's impossible to get along with an ex if we don't want to get back together. I'm here to tell you it is completely possible. Do we really have feelings for all our exes? Because I don't. I'm friends with a few, and getting back together with them wouldn't even cross my mind.
I think that's the situation the woman in this story is talking about. Not all relationships are cookie-cutter. We have to evaluate our situation separately from others. No single rule can be applied to anyone.
When you're in a relationship, you can totally sense whether the vibes are off and whether your partner still has feelings for their ex. Sometimes it happens that they don't, and we should be thankful and normalize the situation. We should even be thankful for it.
We should consider that our partners getting along with an ex with whom they have children is the ideal situation. That speaks well of them and gives us a good prospect of how things could be if we ever separated from their side (I know that's a rather bleak thought, but we should consider stuff like this; you never know who will end up as your ex).
Other people shouldn't have a say in how we manage our relationships or who we bring to our vacation. If we feel we're doing the right thing, why should we listen to someone else?
We should finally make our rules about romantic relationships more flexible and understand that human relationships don't respond to rigid rules; they are all different from one another, and we should be brave enough to live our own story without having it predesigned for us. Question is, are we brave enough?