Hi Michael
I don't know anyone, but I'm sure that it happens.
Whether it is for the best, or not, is another matter.
I feel that if both people in a relationship are to be happy, then both people have to really want to be in that relationship. Otherwise you get two unhappy people, in a sad relationship, when, if they were free from it, they might each find their true soul-mate, who truly wants to be with them.
There is no point at all in trying to get someone back, who doesn't 100% want to be with you ~ because
you just would not be happy, and neither would she.
Now, if it's just a case of sorting out one's life and one's feelings, and then, when sure, committing oneself to a good relationship, that is a different matter.
Also, as in a marriage, sometimes things go wrong because of stress or something else, and partners can either let it go, without a fight, or remember what they once had and try to re-kindle their love. That is worth doing, in my opinion.
The question is, in your case, which scenario is it?
Will things work themselves out, given a bit of time and breathing space?
Could you both benefit from relationship counselling?
Or was this a youthful romance, that has now drifted to a close?
I hope that things work out in your best interests.