The prince is literally the best ex I have ever laid eyes on. No "trying to win her back" or anything. When he switched fiancees, he regretted it, lamented over the FL's "death", and realized that what he was suffering from the horrible new fiancee was "divine punishment". And when he learned that the FL was still alive, he didn't try to chase after her to get back together, when they met again, he treated her with respect, and despite how her father was being a douche and saying that she's mentally ill, the prince believed that she was perfectly sane and granted her the audience she needed.
He might have made a foolish error, but out of all the exes of other stories, this guy is legit the only ex I have the most amount respect for.