Just that really.
Together 10 years. Two kids. After a crush revealed the feeling was mutual, partner announced they had realised they "needed" the freshness and newness of a new love interest. They gave me two options:
a) We stay married but I accept I am just a platonic friend now and the new person will be her main romantic priority (scratch that, main priority full stop so long as the butterflies last).
b) If I can't accept this, I have the right to initiate divorce proceedings.
Option a) was their preference. We did therapy and I was told that I had done nothing wrong. I was actually a very good companion who they admired greatly. However, this new person had been the catalyst for them to realise they had a need to undertake serial monogomous relationships. Newness and mystery were no longer something I could supply and they could not live without experiencing this again (YOLO and all that). Since they needed this, they could not allow themselves to spend the rest of their lives in misery (from denying themselves this). Their misery would = unhappy household which would hurt the kids more than us divorcing.
I did file for divorce in the end. Everything became so toxic - so many secrets and lies - that I had to nuke our family for the sake of all our sanities. No-one else was going to, and yet I was the one who did not want it. But I still struggle with the rationale. My ex admitted the other person could well end up just a fling. They just said the idea of living the rest of their life passing over opportunities to do the whole "falling in love with someone new" roller coaster again was something they found horrifying. So, for the sake of their sanity, they had to break the family up.
A lot is posted on here by people saying that breaking up to meet your "needs" is valid and not selfish. YOLO, again. You can't be expected to live the rest of your life in misery. And I won't deny their right to make that choice - not that they made that choice, rather they forced me to make it for them. But where do "needs" for one's own self-empowerment tip into "needs" for one's own self-interest? Is there even such a distinction? Is there no such thing as selfishness - only self-enabling that others judge unfairly?