this is kind of sad but who would be keen on recognizing that a relationship isnt what it used to be and maybe s/o and them aren't the best together for whaever reason anymore despite still caring for one another?
I think that out of the four, Ignis would be the most understanding in a situation like this.
As opposed to the others, Iggy would be able to step outside of the situation and realize that he and his s/o have just grown apart. He understands that it’s a part of getting older and growing up, and he realizes that they’ve just grown separately from one another rather than together. He’s also the type to actually mean it when he says that he wants to be their friend, and makes a concerted effort to be warm towards his s/o when they decide to end their romantic relationship. He still respects them and wants them to be happy, he just also realizes that he unfortunately isn’t the one who is going to be able to provide that happiness.